Reception method, transmission method, reception device, and transmission device

ABSTRACT

According to one aspect of the present disclosure, a reception method in broadcast and broadband cooperation service, the reception method includes: receiving broadcast content transmitted through broadcast; receiving acquisition information through the broadcast, the acquisition information being information used to play back broadband content transmitted through broadband while the broadband content is synchronized with the received broadcast content, the acquisition information being information relating to acquisition of the broadband content; and acquiring the broadband content based on the received acquisition information. Therefore, the broadband content can properly be acquired in response to the reception of the broadcast content.

BACKGROUND 1. Technical Field

The present disclosure relates to a reception method and the like forsynchronously playing back pieces of content such as video, audio, andcaption, which are obtained through broadcast or broadband

2. Description of the Related Art

Nowadays, there are provided various kinds of services in which thebroadcast and the broadband cooperate with each other.

For example, the following reception devices are proposed as a devicethat provides enjoyment of such kinds of services (for example, see PTLs1, 2, and 3).

The reception device receives broadcast content from a digital broadcastsignal, receives broadband content linking with the broadcast contentthrough a broadband network, and synchronously presents the broadcastcontent and the broadband content.

CITATION LIST Patent Literatures

PTL 1: Unexamined Japanese Patent Publication No. 2013-9332

PTL 2: Unexamined Japanese Patent Publication No. 2013-9359

PTL 3: Unexamined Japanese Patent Publication No. 2013-9341

SUMMARY

In one general aspect, the techniques disclosed here feature a receptionmethod in broadcast and broadband cooperation service, the receptionmethod includes: receiving broadcast content transmitted throughbroadcast; receiving acquisition information through the broadcast, theacquisition information being information used to play back broadbandcontent transmitted through broadband while the broadband content issynchronized with the received broadcast content, the acquisitioninformation being information relating to acquisition of the broadbandcontent; and acquiring the broadband content based on the receivedacquisition information.

Additional benefits and advantages of the disclosed embodiments willbecome apparent from the specification and drawings. The benefits and/oradvantages may be individually obtained by the various embodiments andfeatures of the specification and drawings, which need not all beprovided in order to obtain one or more of such benefits and/oradvantages.

These comprehensive or specific aspects may be implemented by a system,a device, an integrated circuit, a computer program, or a recordingmedium such as a computer-readable CD-ROM. These comprehensive orspecific aspects may be implemented by any combination of the system,the device, the integrated circuit, the computer program, and therecording medium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a configuration of receptiondevice 1 according to a first exemplary embodiment of the presentdisclosure;

FIG. 2 is a block diagram illustrating a configuration example ofbuffers 13 and 22 in FIG. 1,

FIG. 3 is a view illustrating an example of a state transition ofcontent presentation in reception device 1 of FIG. 1;

FIG. 4 is a view illustrating a signal image for explaining an exampleof the method for synchronously presenting the broadcast content and thebroadband content in the content presentation state transition of FIG.3;

FIG. 5 is a flowchart illustrating an example of processing operation ofthe method for synchronously presenting the broadcast content and thebroadband content in reception device 1 of FIG. 1;

FIG. 6 is a view illustrating a signal image for explaining anotherexample of the synchronous presentation method;

FIG. 7 is a view illustrating a signal image for explaining stillanother example of the synchronous presentation method;

FIG. 8 is a flowchart illustrating another example of the processingoperation of the synchronous presentation method;

FIG. 9 is a block diagram illustrating a configuration of receptiondevice 1A according to a modification of the first exemplary embodiment;

FIG. 10 is a block diagram illustrating a configuration of receptiondevice 1B according to another modification of the first exemplaryembodiment;

FIG. 11 is a view illustrating an example of a setting menu screen;

FIG. 12 is a view illustrating an example of a synchronous presentationmethod setting screen;

FIG. 13 is a view illustrating an example of a synchronous presentationmanual setting screen;

FIG. 14 is a block diagram illustrating a configuration of receptiondevice 100 according to a second exemplary embodiment of the presentdisclosure;

FIG. 15 is a block diagram illustrating a configuration example ofcontrol manager 141 in FIG. 14;

FIG. 16 is a flowchart illustrating an example of initial operation of adelay buffer and a de-jitter buffer after reception device 100 in FIG.14 starts broadcast and broadband reception;

FIG. 17 is a flowchart illustrating an example of control methoddeciding operation of control method determiner 174 in FIG. 14;

FIG. 18 is a block diagram illustrating a configuration of receptiondevice 100A according to a modification of the second exemplaryembodiment;

FIG. 19 is a flowchart illustrating an example of broadband contentacquiring operation of a reception device according to a third exemplaryembodiment;

FIG. 20 is a flowchart illustrating an example of synchronous playbackoperation including the broadband content acquisition;

FIG. 21 is a flowchart illustrating an example of operation in which abroadcast and broadband cooperation service is started in a middle of aprogram;

FIG. 22 is a flowchart illustrating an example of buffering operationfor the broadband content;

FIG. 23 is a flowchart illustrating an example of a determinationwhether the broadband content can be acquired anytime;

FIG. 24 is a flowchart illustrating an example of operation when delaypresentation of the broadcast content is not permitted;

FIG. 25 is a block diagram illustrating a configuration of atransmission device; and

FIG. 26 is a flowchart illustrating an example of operation of thetransmission device.

DETAILED DESCRIPTION

The broadcast content is usually transmitted from a broadcast station ata predetermined clock time. Therefore, in the case that the broadcastcontent and the broadband content are synchronously presented (playedback), the reception device acquires and plays back the broadbandcontent according to the reception of the broadcast content.

However, in the reception device, there is a limit to such the broadbandcontent acquisition as a capacity of a broadband content buffer. Forthis reason, there is room for study of a method for acquiring thebroadband content of the reception device.

(First Knowledge Underlying the Present Disclosure)

The reception device disclosed in PTL 1 receives the broadcast contentthrough the digital broadcast signal, and receives the broadband contentlinking with the broadcast content through the broadband network. Thereception device temporarily stores the received broadcast content in afirst synchronizing buffer, and temporarily stores the receivedbroadband content in a second synchronizing buffer. The reception devicecontrols an output time of the content output from one of the first andsecond synchronizing buffers according to a time specified by commandexecuter, and delays the presentation of one of the broadcast contentand the broadband content. Therefore, the broadcast content andbroadband content having different reception clock times cansynchronously be presented.

The reception device disclosed in PTL 2 synchronizes the broadcastcontent presentation and the broadband content presentation by delayingthe broadcast content presentation. In the reception device, thebroadband content is acquired in response to an external manipulation oran external control signal to start delay presentation in which thebroadcast content is presented while being delayed compared to apresentation clock time of the normal presentation after the broadbandcontent acquisition is completed. This enables the broadcast content tobe normally presented even during acquisition of the broadband content.

In the conventional reception devices disclosed in PTLs 1 and 2, inswitching a state in which the broadcast content is played back whilethe broadband content is not played back to a state in which both thebroadcast content and the broadband content are played back, it isnecessary to delay the broadcast content presentation according to adelay time of the reception clock time of the broadband content to thereception clock time of the broadcast content. Therefore, the broadcastcontent presented to a viewer is interrupted. An influence on the viewerincreases with increasing delay time of the reception clock time of thebroadband content to the reception clock time of the broadcast content.

The similar problem is generated in the case that the reception clocktime of the broadcast content is delayed with respect to the receptionclock time of the broadband content. That is, in switching the state inwhich the broadband content is played back while the broadcast contentis not played back to the state in which both the broadband content andthe broadcast content are played back, it is necessary to delay thebroadband content presentation according to the delay time of thereception clock time of the broadcast content to the reception clocktime of the broadband content. Therefore, the broadband contentpresented to the viewer is interrupted. The influence on the viewerincreases with increasing delay time of the reception clock time of thebroadcast content to the reception clock time of the broadband content.

However, currently a technical solution to the problem is not studiedyet.

Therefore, the inventors have studied the technical solution to theproblem.

As a result of the study, the inventors have obtained knowledge that theinfluence on the viewer is reduced by notifying the viewer of thesynchronization between the broadcast and the broadband before and afterthe broadcast content presentation is delayed or before and after thebroadband content presentation is delayed.

Hereinafter, exemplary embodiments based on the solution obtained basedon the knowledge will be described.

First Exemplary Embodiment

FIG. 1 is a block diagram illustrating a configuration of receptiondevice 1 that is a broadcast and broadband cooperation reception deviceaccording to a first exemplary embodiment of the present disclosure.

Reception device 1 includes digital broadcast receiver 11, separator 12,buffer 13, decoder 14, broadband transmitter and receiver 21, buffer 22,decoder 23, content generator 31, broadband transmitter and receiver 41,manipulation input section 42, and controller 51.

For example, reception device 1 is a device such as a televisionreceiver, a portable television set, a recorder, a set-top box, asmartphone, and a tablet.

A digital broadcast signal received by external broadcast antenna 3 isinput to digital broadcast receiver 11. Digital broadcast receiver 11tunes a desired channel from the digital broadcast signal, performsdemodulation processing and error correction processing on the digitalbroadcast signal of the tuned desired channel to generate a transportstream, and outputs the transport stream to separator 12. Alternatively,reception device 1 may include broadcast antenna 3.

As used herein, for example, the digital broadcast means terrestrialdigital broadcast, BS (Broadcast Satellite) digital broadcast, CS(Broadbands Satellite) digital broadcast, cable television, andbroadcast in which an IP (Internet Protocol) network such as an opticalfiber is used.

Separator 12 separates the transport stream generated by digitalbroadcast receiver 11 into video data, audio data, data broadcast, andthe like. Separator 12 acquires various pieces of control informationincluded in the transport stream.

Examples of the control information included in the transport streaminclude PSI (Program Specific Information) of system information, SI(Service Information), a PCR (Program Clock Reference) ofsynchronization information, and an application data table (ApplicationInformation Table (AIT)) of information on an application. For example,an application ID identifying the application, a control code that cancontrol a life cycle such as activation and termination of theapplication, and location information on the application are describedin the AIT.

The video data, the audio data, and the like, which are output fromseparator 12, are constructed as a PES (Packetized Elementary Stream)packet. A PTS (Presentation Time Stamp) and a DTS (Decoding Time Stamp)are stored as synchronizing presentation clock time information in a PESheader included in each PES packet. One of the PTS and the DTS or boththe PTS and the DTS are occasionally included in the PES header.

The separated video data, audio data, and the like are output fromseparator 12 to buffer 13, and the PCR, the AIT, and the like are outputfrom separator 12 to controller 51.

The video data, the audio data, and the like, which are output fromseparator 12, are stored in buffer 13. At the timing indicated bycontroller 51, buffer 13 outputs content data of each component such asthe video and the audio to one of or both decoder 14 and broadbandtransmitter and receiver 41 in units of PES packets. Buffer 13 isdescribed in detail later with reference to FIG. 2.

Decoder 14 converts the PES packet of each component, such as the videoand the audio, which is output from buffer 13, into an elementary stream(ES) to extract the PTS and the DTS from a PES header of the PES packet.Decoder 14 outputs the extracted PTS and DTS to controller 51. Decoder14 decodes the elementary stream in each component, and outputs thedecoded elementary stream to content generator 31. In the case thatorder of a pre-decoding picture frame of video content differs fromorder of a post-decoding picture frame, decoder 14 replaces the orderusing a buffer included in decoder 14, and outputs the picture frame tocontent generator 31.

Broadband transmitter and receiver 21 acquires the application and AVcontent from a content server provided by an business operator relatingto a broadcast organization or other business operators through abroadband network. Sometimes broadband transmitter and receiver 21acquires the control information on the AIT and the like through thebroadband network. Examples of the AV content provided by a broadbandprovider include file data, video data, and audio data. Broadbandtransmitter and receiver 21 outputs the acquired application and controlinformation to controller 51. Broadband transmitter and receiver 21outputs the acquired AV content to buffer 22.

For example, broadband transmitter and receiver 21 and broadbandtransmitter and receiver 41 conduct broadband by a broadband methodpursuant to a broadband standard such as wireless LAN (Local AreaNetwork), Bluetooth (registered trademark), Ethernet (registeredtrademark), USB (Universal Serial Bus), PLC (Power Line Broadband), andHDMI (registered trademark) (High-Definition Multimedia Interface).Broadband transmitter and receiver 21 and broadband transmitter andreceiver 41 may have either an identical configuration or differentconfigurations.

The content data of the AV content output from broadband transmitter andreceiver 21 is stored in buffer 22. At the time indicated by controller51, buffer 22 outputs content data of each component such as the videoand the audio to one of or both decoder 23 and broadband transmitter andreceiver 41 in units of PES packets. Buffer 22 is described in detaillater with reference to FIG. 2.

Decoder 23 converts the PES packet of each component, such as the videoand the audio, which is output from buffer 22, into the elementarystream (ES) to extract the PTS and the DTS from the PES header of thePES packet. Decoder 23 outputs the extracted PTS and DTS to controller51. Decoder 23 decodes the elementary stream in each component, andoutputs the decoded elementary stream to content generator 31. In thecase that the order of the pre-decoding picture frame of the videocontent differs from the order of the post-decoding picture frame,decoder 23 replaces the order using a buffer included in decoder 23, andoutputs the picture frame to content generator 31.

Content generator 31 generates a service presentation content accordingto the instruction of controller 51 using the content data of eachcomponent (such as the video, the audio, and the caption) output fromdecoder 14 and the content data of each component (such as the video,the audio, and the caption) output from decoder 23. The presentationcontent generated by content generator 31 is output to externalpresentation section 5, and presented by presentation section 5.Alternatively, reception device 1 may include presentation section 5.

Broadband transmitter and receiver 41 conducts broadband with a contentpresenting device different from presentation section 5 and an inputinterface manipulated by the viewer. Examples of the content presentingdevice include a television receiver, a portable television set, asmartphone, and a tablet. Broadband transmitter and receiver 41transmits the PES packet output from buffers 13 and 22 to the contentpresenting device. Broadband transmitter and receiver 41 transmits thedata received from controller 51 to the content presenting device.Examples of the input interface include a remote controller, a tabletterminal, a smartphone, and a keyboard, a mouse, a camera, and amicrophone of a personal computer. Broadband transmitter and receiver 41outputs input details received from the input interface to manipulationinput section 42 or controller 51. The content presenting device and theinput interface may be either an identical device or different devices.

Manipulation input section 42 acquires a control signal from theexternal input interface or the built-in input interface in response toa viewer's manipulation with the input interface, and transmits thecontrol information corresponding to the acquired control signal tocontroller 51. Examples of the input interface include a remotecontroller, a tablet terminal, a smartphone, and a keyboard, a mouse, acamera, and a microphone of a personal computer. For example, theviewer's manipulation with the input interface means press-down of abutton physically disposed or virtually disposed on a screen, a gesture,a manipulation by sound, and a combination thereof. The control signalmay be input from the input interface to manipulation input section 42through broadband transmitter and receiver 41, or directly input fromthe input interface to controller 51 through broadband transmitter andreceiver 41. In the case that the control signal is directly input fromthe input interface to controller 51 through broadband transmitter andreceiver 41, reception device 1 does not need to include manipulationinput section 42.

Controller 51 generates a reference clock signal using the PCR outputfrom separator 12. For example, the generated reference clock signal isused to control output timing of buffers 13 and 22.

Using the PTS output from decoder 14, controller 51 generates thecontrol information in order to match the output timing of each piece ofcontent (such as the video content and audio content) transmittedthrough the broadcast, and outputs the control information to PES buffer71 of buffer 13. Using the PTS output from decoder 23, controller 51generates the control information in order to match the output timing ofeach piece of content (such as the video content and the audio content)transmitted through the broadband, and outputs the control informationto PES buffer 71 of buffer 22.

Controller 51 calculates the delay time between the broadcast contentand the broadband content using the PTS output from decoder 14 and thePTS output from decoder 23. Controller 51 generates the controlinformation in order to match the output timing of the broadcast contentto the output timing of the broadband content based on the calculateddelay time, and outputs the control information to synchronizing buffers72 of buffers 13 and 22. Controller 51 provides content generator 31with instruction about announcement (synchronous presentationannouncement) to the viewer relating to the synchronization between thebroadcast content and the broadband content.

For example, the synchronous presentation announcement meansannouncement of generation of discontinuous video presentation to theviewer in switching normal presentation (described later) of thebroadcast content to delay presentation (described later), orannouncement of generation of video overlapping presentation to theviewer. The synchronous presentation announcement including is describedlater with reference to a specific example.

A configuration example of buffers 13 and 22 will be described belowwith reference to FIG. 2. Because buffers 13 and 22 have the identicalconfiguration, buffers 13 and 22 are collectively described.

FIG. 2 is a block diagram illustrating a configuration example ofbuffers 13 and 22 in FIG. 1.

Each of buffers 13 and 22 includes PES buffer 71 and synchronizingbuffer 72.

PES buffer 71 is used to match the output timing of each piece ofcontent such as the video content and the audio content. PES buffer 71converts each piece of content such as the video content and the audiocontent into the PES packet, and outputs the content data in units ofPESs at the output timing indicated by the control information fromcontroller 51.

Synchronizing buffer 72 is used to match the output timing between thebroadcast content and the broadband content. Synchronizing buffer 72outputs the content data in units of PESs at the timing indicated by thecontrol information from controller 51.

PES buffer 71 and synchronizing buffer 72 can output the content data inunits of PESs with any delay time and at any output timing, and thedelay time and the output timing are completely indicated by controller51.

A synchronous presentation method in which the broadcast content and thebroadband content are presented while the output timing of the broadcastcontent is matched to the output timing of the broadband content will bedescribed below.

The broadcast and broadband cooperation service includes a method forcontrolling the broadcast and broadband cooperation by an applicationsuch as HTMLS and a method for controlling the broadcast and broadbandcooperation with no use of the application. In the followingdescription, by way of example, the broadcast and broadband cooperationservice is provided by the application. The application may be an HTMLSapplication or a resident application of a receiving apparatus. Theresident application or a part of a function of the receiving apparatusmay be provided as the API, and controlled by another application suchas HTMLS.

The broadcast and broadband cooperation service includes a dependenttype service in which the application links with the AV content and anindependent type service in which the application does not link with theAV content. There are various pieces of broadband content.

A use case in which the broadband content linking with the broadcastcontent is presented in the dependent type service linking with thebroadcast content is considered in the following description. It isassumed that the broadband content is multicast distribution ofreal-time live video in which the packet cannot previously be acquired.

FIG. 3 illustrates an example of a state transition of the contentpresentation in reception device 1, and FIG. 3 is used to explain aspecific example of the method for synchronously presenting thebroadcast content and the broadband content.

In the state transition diagram of FIG. 3, reception device 1 is startedfrom a power-off state (a state of broadcast off and broadband off). Byturning to the broadcast content presentation-on state, reception device1 makes a transition from the state of broadcast off and broadband offto a state in which only the broadcast content is presented (a state ofbroadcast on and broadband off). By turning to the broadband contentpresentation-on state, reception device 1 makes the transition from thestate of broadcast on and broadband off to a state in which both thebroadcast content and the broadband content are presented (a state ofbroadcast on and broadband on).

Hereinafter, “the state of broadcast on and broadband off” is defined asa “state A”, and “the state of broadcast on and broadband on” is definedas a “state B”. A period until the transition is completed since thetransition from the “state A” to the “state B” is decided is defined asa “transition period”.

The broadcast and broadband cooperation service is provided on theassumption that the application is activated. Therefore, in the casethat the application is not activated in providing the broadcast andbroadband cooperation service, it is necessary to activate theapplication. In order to provide only the broadcast service, theapplication is not necessarily activated.

For example, in the transition from the state A to the state B, it isnecessary to activate the application in the case that the applicationis not activated in the state A. At this point, the application isactivated based on the AIT included in the broadcast signal.

Examples of application activation timing include the case that theviewer explicitly specifies the application activation timing based onthe AIT stored in the broadcast content or broadband content and thecase that the application is automatically activated by linking with thecontent based on AIT application activation information. Examples ofapplication termination timing include the case that the viewerexplicitly specifies the application termination timing based on the AITstored in the broadcast content or broadband content and the case thatthe application is automatically terminated by linking with the contentbased on AIT application termination information.

Examples of a method for putting the broadband content into the on stateduring the presentation of the broadcast content include a method forexplicitly specifying the on state of the broadband content by theviewer based on the AIT stored in the broadcast content and a method forautomatically activating the broadband content based on the AIT storedin the broadcast content.

In general, because the reception of the broadband content is largelydelayed compared with the reception of the broadcast content, thebroadband content is received while delayed with respect to thebroadcast content on the reception side in the case that the live videois transmitted through the broadcast and broadband.

In order to start the presentation of the broadband content during thepresentation of the broadcast content, and in order to presentsynchronously present the broadcast content and the broadband content,it is necessary that the broadcast content be presented while delayed.

An example of the method for synchronously presenting the broadcastcontent and the broadband content in the state transition of the contentpresentation in FIG. 3 will be described with reference to FIGS. 4 and5.

FIG. 4 is a view illustrating a signal image for explaining an exampleof the method for synchronously presenting the broadcast content and thebroadband content in the content presentation state transition of FIG.3.

FIG. 4(a) illustrates a time signal of the broadcast content with nodelay. The case that the broadcast presentation is performed using thetime signal in FIG. 4(a) is defined as “normal presentation”.

FIG. 4(b) illustrates a time signal of the delayed broadcast content.The case that the broadcast presentation is performed using the timesignal in FIG. 4(b) is defined as “delay presentation”. “D” in FIG. 4(b)indicates the delay time of the reception clock time of the broadbandcontent to the reception clock time of the broadcast content.

FIG. 4(c) illustrates a time signal of the broadband content.

FIG. 4(d) illustrates a time signal of the actually-presented broadcastcontent.

FIG. 4(e) illustrates a time signal of the actually-presented broadbandcontent.

Reception device 1 performs normal presentation of the broadcast contentin a period to clock time T1 at which the broadband content acquisitionis started and a period from clock time T1 to clock time T2 at which thepreparation for the broadband content presentation is completed, namely,until the transition from the state A to the state B is completed.

Reception device 1 presents the broadband content while performing delaypresentation of the broadcast content in the period after clock time T2at which the preparation for the broadband content presentation iscompleted, namely, after the transition from the state A to the state Bis completed.

Thus, the presentation of the broadcast content is switched from thenormal presentation to the delay presentation at the timing to completethe transition from the state A to the state B. Therefore, thepresentation of the broadcast content becomes discontinuous videopresentation and the like at the timing to complete the transition fromthe state A to the state B. For a while after the delay presentation isstarted, the presentation of the broadcast content becomes theoverlapping presentation such as the video identical to the videopresented once in the normal presentation. Possibly the discontinuousvideo presentation or the video overlapping presentation gives anuncomfortable feeling to the viewer, and occasionally gives discomfortto the viewer.

Therefore, reception device 1 provides announcement (synchronouspresentation announcement) relating to the synchronization between thebroadcast content and the broadband content to the viewer during abroadcast content overlapping presentation period (for example, amessage that “the overlapping presentation of the broadcast content isperformed in order to synchronize the broadcast content with thebroadband content” is presented in presentation section 5).

The performance of the synchronous presentation announcement allows theviewer to understand a reason of the discontinuous video presentation orthe video overlapping presentation, and the uncomfortable feeling ordiscomfort given to the viewer can be relaxed.

FIG. 5 is a flowchart illustrating an example of processing operation ofthe method for synchronously presenting the broadcast content and thebroadband content by reception device 1 in the content presentationstate transition of FIG. 3. At a time point the flowchart in FIG. 5 isstarted, reception device 1 is in a power-off state (the state ofbroadcast off and broadband off).

By turning to the broadcast content presentation-on state, receptiondevice 1 makes the transition from the power-off state (the state ofbroadcast off and broadband off) to the state of broadcast on andbroadband off (state A) (Step S11). Reception device 1 starts thebroadcast content acquisition, and starts the normal presentation of thebroadcast content (Step S12).

Reception device 1 starts the broadband content acquisition in responseto the application acquisition (Step S13).

Reception device 1 determines whether the preparation for the broadbandcontent presentation is completed (Step S14). The processing in Step S14is performed until the preparation for the broadband contentpresentation is completed (No in S14). The processing in Step S15 isstarted when the preparation for the broadband content presentation iscompleted (Yes in S14). For example, the determination that thepreparation for the broadband content acquisition is completed is madewhen the content data of the broadband content of a predetermined amountis stored in buffer 22.

In reception device 1, controller 51 compares the PTS of the decodedbroadcast content to the PTS of the broadband content to calculate thedelay time of the broadband content to the broadcast content (Step S15).

Controller 51 generates the control information in order to match theoutput timing of the broadcast content to the output timing of thebroadband content based on the delay time calculated in Step S15, andoutputs the control information to synchronizing buffers 72 of buffers13 and 22. Synchronizing buffer 72 of buffer 13 delays buffer outputbased on the delay time calculated in Step S15 according to the controlinformation, and synchronizing buffer 72 of buffer 22 performs bufferoutput according to the control information. Thus, reception device 1switches the broadcast content presentation from the normal presentationto the delay presentation to start the delay presentation, and startsthe broadband content presentation at the same time. Controller 51instructs content generator 31 to present a synchronous presentationannouncement message (for example, “the overlapping presentation of thebroadcast content is performed in order to synchronize the broadcastcontent and the broadband content with each other”), and contentgenerator 31 starts the presentation of the synchronous presentationannouncement message in presentation section 5 based on the instruction(Step S16).

Controller 51 determines whether the overlapping presentation of thebroadcast content is ended based on the delay time calculated in StepS15 (Step S17). The processing in Step S17 is performed until theoverlapping presentation of the broadcast content is completed (No inS17). When the overlapping presentation of the broadcast content isended (Yes in S17), controller 51 instructs content generator 31 to endthe presentation of the synchronous presentation announcement message,and content generator 31 ends the presentation of the message forannouncing synchronization in presentation section 5 based on theinstruction (Step S18).

(Supplements of First Exemplary Embodiment)

Supplements of the first exemplary embodiment will be described below.

(1) In the first exemplary embodiment, the method for synchronouslypresenting the broadcast content and the broadband content is describedby way of example. However, the synchronous presentation method is notlimited to the method of the first exemplary embodiment.

FIG. 6 is a view illustrating a signal image for explaining anotherexample of the synchronous presentation method, and for example, thesynchronous presentation method in FIG. 6 may be adopted. The timesignals in (a) to (e) of FIG. 6 are similar to those in (a) to (e) ofFIG. 4.

In the synchronous presentation method of FIG. 4, the normalpresentation of the broadcast content is performed in the statetransition period, namely, in the period until the preparation for thebroadband content presentation is completed since the broadband contentacquisition is started.

On the other hand, in the synchronous presentation method of FIG. 6, thebroadcast content presentation is interrupted to black out the screen ofpresentation section 5 in the state transition period, namely, in theperiod until the preparation for the broadband content presentation iscompleted since the broadband content acquisition is started. At thesame time, reception device 1 presents a message in presentation section5 to the viewer for the purpose of the synchronous presentationannouncement. For example, the message indicates that reception device 1is in a standby state for the synchronization between the broadcastcontent and the broadband content.

Various synchronous presentation methods can be performed by changing abuffer clock timing control method or presentation timing. FIG. 7 is aview illustrating a signal image for explaining still another example ofthe synchronous presentation method, and for example, the synchronouspresentation method in FIG. 7 may be adopted. The time signals in (a) to(e) of FIG. 7 are similar to those in (a) to (e) of FIG. 4.

In the synchronous presentation method of FIG. 7, reception device 1starts slow playback of the broadcast content in response to thebroadband content acquisition, and makes the transition to the state inwhich the delay presentation of the broadcast content and the broadbandcontent presentation are performed while the completion of thepreparation for the broadband content presentation is compared to theplayback time of the broadcast content. At the same time, receptiondevice 1 presents a message in presentation section 5 to the viewer forthe purpose of the synchronous presentation announcement. For example,the message indicates that reception device 1 currently performs theslow playback of the broadcast content for the synchronization betweenthe broadcast content and the broadband content. The slow playback canbe performed by widening a time interval of the buffer output. The delayis gradually adjusted by the slow playback of the broadcast content, andthe broadcast content and the broadband content are synchronouslypresented when the delay adjustment is completed to match the broadcastcontent presentation clock time to the broadband content presentationclock time. In this case, the clock time at which the preparation forthe broadband presentation is completed is not matched to thesynchronous presentation timing.

Controller 51 controls the playback timing and the clock. Controller 51outputs the proper presentation or the presentation timing to contentgenerator 31 according to the synchronous presentation method.

In the synchronous presentation method of FIG. 7, when the broadcastcontent and the broadband content are synchronously presented, thebroadcast content and the broadband content can more smoothly bepresented.

(2) In the synchronous presentation method of the first exemplaryembodiment, the broadcast content presentation is switched from thenormal presentation to the delay presentation in response to thecompletion of the preparation for the broadband content. Alternatively,for example, the broadcast content may previously be presented whiledelayed. This example will be described with reference to a flowchart inFIG. 8. At the time point the flowchart in FIG. 8 is started, receptiondevice 1 is in a power-off state (the state of broadcast off andbroadband off).

By turning to the broadcast content presentation-on state, receptiondevice 1 makes the transition from the power-off state (the state ofbroadcast off and broadband off) to the state of broadcast on andbroadband off (Step S51). Reception device 1 starts the broadcastcontent acquisition, and starts the normal presentation of the broadcastcontent (Step S52).

In the normal presentation of the broadcast content, reception device 1activates an application for performing the delay presentation of thebroadcast content (hereinafter, referred to as a “delay presentationapplication”) as a first application (Step S53). Examples of thebroadcast delay presentation timing include timing specified by theviewer, timing specified by the broadcast organization or other businessoperators using the broadband or broadcast AIT, and timing specified byan application acquired based on the AIT.

In reception device 1, after the delay presentation application isactivated, controller 51 acquires the broadband content, and comparesthe PTS of the decoded broadcast content to the PTS of the broadbandcontent to calculate the delay time of the broadband content to thebroadcast content (Step S54).

Controller 51 controls output delay of synchronizing buffer 72 of buffer13 based on the delay time calculated in Step S54, whereby receptiondevice 1 switches the broadcast content presentation from the normalpresentation to the delay presentation to start the delay presentation.Controller 51 instructs content generator 31 to present a synchronouspresentation announcement message (for example, “the overlappingpresentation of the broadcast content is performed in order tosynchronize the broadcast content and the broadband content with eachother”), and content generator 31 starts the presentation of thesynchronous presentation announcement message in presentation section 5based on the instruction (Step S55).

Controller 51 determines whether the overlapping presentation of thebroadcast content is ended based on the delay time calculated in StepS54 (Step S56). The processing in Step S56 is performed until theoverlapping presentation of the broadcast content is completed (No inS56). When the overlapping presentation of the broadcast content isended (Yes in S56), controller 51 instructs content generator 31 to endthe presentation of the synchronous presentation announcement message,and content generator 31 ends the presentation of the synchronouspresentation announcement message in presentation section 5 based on theinstruction (Step S57).

In the state of broadcast on and broadband off and in the delaypresentation of the broadcast content, reception device 1 starts asecond application and therefore starts the broadband contentacquisition (Step S58).

Reception device 1 determines whether the preparation for the broadbandcontent presentation is completed (Step S59). The processing in Step S59is performed until the preparation for the broadband contentpresentation is completed (No in S59). When the preparation for thebroadband content presentation is completed (Yes in S59), receptiondevice 1 starts the broadband content presentation (Step S60).

For a program having a possibility of the delay presentation, thesynchronous presentation of the broadcast content and the broadbandcontent can smoothly be performed by previously performing the delaypresentation of the broadcast content at timing of, for example, thestarting of the broadcast reception, the tuning, or CM (CommercialMessage) timing, at which the viewer has the small uncomfortablefeeling.

For example, the synchronous presentation announcement message does notneed to be presented depending on timing at which the delay presentationof the broadcast content is disclosed (for example, in the starting ofthe broadcast reception or the tuning)

(3) In the synchronous presentation method of the first exemplaryembodiment, the details and period of the announcement (synchronouspresentation announcement) relating to the synchronous presentation ofthe broadcast content and the broadband content to the viewer aredescribed by way of example.

The synchronous presentation announcement including the detailsdescribed in the first exemplary embodiment will be described below.

Examples of the details of the synchronous presentation announcementinclude the presentation of the message relating to the synchronouspresentation of the broadcast content and the broadband and thepresentation of the discontinuous video animation.

Specifically, for example, the presentation is performed as follows.

-   -   A message, an icon, or the like indicating the set synchronous        presentation method to the viewer is displayed.    -   A message, an icon, or the like indicating that discontinuous        video display will be generated or already generated to the        viewer is displayed.    -   A message, an icon, or the like indicating that the overlapping        presentation of the video is performed to the viewer is        displayed.    -   An animation function is inserted between videos in order to        eliminate the discontinuous display.

Other examples than the message or icon display include telop displayand audio output. The presentation may be performed using an externaldevice.

Examples of the synchronous presentation announcement timing or periodinclude the period during which the overlapping presentation of thebroadcast content is performed, the period until the overlappingpresentation of the broadcast content is ended since the broadbandcontent acquisition is started, the application activation timing, thetiming at which the preparation for the broadband content is completed,and the timing or period according to an even of reception device 1. Thetiming of an interface manipulation performed by the viewer is alsoincluded in the example of the synchronous presentation announcementtiming or period. The synchronous presentation announcement may beperformed only while the viewer permits the synchronous presentationannouncement.

For example, controller 51 decides the details, timing, or period of thesynchronous presentation announcement according to the synchronouspresentation method specified by the application, a predetermined rule,or the setting of the reception device, and instructs content generator31 on the details, timing, or period of the synchronous presentationannouncement. Content generator 31 performs the synchronous presentationannouncement according to the details decided in the timing or perioddecided in response to the instruction of controller 51. The setting ofthe reception device may, but not necessarily, be determined by theviewer.

The broadcast organization, a business operator relating to thebroadcast organization, or other business operators may issue theinstruction of the details, timing, or period of the synchronouspresentation announcement according to the content by embedding acontrol signal indicating the details, timing, or period of thesynchronous presentation announcement in the broadcast or broadband.

(4) In the first exemplary embodiment, the broadband content acquisitiontiming is identical to the application acquisition timing.Alternatively, the broadband content acquisition timing may be differentfrom the application acquisition timing. For example, the broadbandcontent acquisition timing follows the instruction of the application.

(5) In the first exemplary embodiment, by way of example, the statetransition of reception device 1 is described as illustrated in FIG. 3.However, the state transition is not limited to that in FIG. 3 but maybe as follows.

It is necessary for reception device 1 to delay the broadcast contenteven in the state transition from the state in which the normalpresentation of the broadcast content is provided while an independentbroadband application that does not link with the content is currentlyactivated (a state of broadcast on, broadband independent applicationon, and linkage application off) to a state in which an applicationlinking with the broadcast is activated (a state of broadcast on,broadband independent application on, and linkage application on). Thiscase can also be applied with the synchronous presentation methodssubstantially identical to those of the first exemplary embodiment andthe supplements of the first exemplary embodiment or the synchronouspresentation announcement substantially identical to those of thesynchronous presentation method.

(6) In the first exemplary embodiment or the supplement (2) of the firstexemplary embodiment, the delay time between the broadcast content andthe broadband content is calculated using the PTS output after thedecoding. Alternatively, the delay time may be calculated using the DTS,or the delay time may be calculated using both the PTS and the DTS. Thedelay time may also be calculated using the pre-decoding PTS or DTS. Thedelay time may also be calculated using PCR, a clock (STC) generatedbased on the PCR, the PTS, or the DTS. In the case that the referenceclock is an NTP, the delay time may be calculated using the NTP. In thecase that different reference clocks are used in the broadcast contentand the broadband content, the delay time may be calculated usingtimeline auxiliary information indicating a correspondence relationshipbetween the respective reference clocks.

The buffer control timing is calculated in consideration of a site wherethe PTS or DTS is calculated or a buffer position. The followingconfiguration can be used as an example in which the site where the PTSor DTS is calculated or the buffer position varies.

In the first exemplary embodiment, decoder 14 extracts the PTS or DTS.Alternatively, the conversion of the PES packet into the ES and theextraction of the PTS or DTS may be processed by not decoder 14 but PESbuffer 71 of buffer 13. In this case, desirably the positions of PESbuffer 71 and synchronizing buffer 72 are replaced with each other inbuffer 13. PES buffer 71 outputs the extracted PTS or DTS to controller51. At the timing indicated by controller 51, PES buffer 71 outputs thecontent data of each component such as the video and the audio to one ofor both decoder 14 and broadband transmitter and receiver 41. Similarly,the conversion of the PES packet into the ES and the extraction of thePTS or DTS may be processed by not decoder 23 but PES buffer 71 ofbuffer 22. In this case, desirably the positions of PES buffer 71 andsynchronizing buffer 72 are replaced with each other in buffer 22. PESbuffer 71 outputs the extracted PTS or DTS to controller 51. At thetiming indicated by controller 51, PES buffer 71 outputs the contentdata of each component such as the video and the audio to one of or bothdecoder 23 and broadband transmitter and receiver 41. The aboveconfiguration is equal to a configuration of a second exemplaryembodiment, and PES buffer 71 in FIG. 2 corresponds to separation buffer114 in FIGS. 14 and 18.

(7) In the first exemplary embodiment, at the timing indicated bycontroller 51, the content data of each component such as the video andthe audio is output to broadband transmitter and receiver 41 in units ofPES packets, and broadband transmitter and receiver 41 transmits thecontent data and the data received from controller 51 to the contentpresenting device. More specifically, in broadband transmitter andreceiver 41, an access unit of each component such as the video and theaudio, the PES packet, and the control information or clock informationinput from controller 51 are re-multiplexed using a specificmultiplexing scheme, and transmitted to the cooperation terminal.Examples of the multiplexing scheme include MP4, MPEG2-TS, MPEG-DASH,and MMT.

(8) In the first exemplary embodiment, the broadband content is delayedby a constant time with respect to the broadcast content. It is alsoconceivable that the broadcast content is delayed with respect to thebroadband content. In this case, the broadcast content is presented inone pattern of the normal presentation, and the broadband content ispresented in two patterns of the normal presentation and delaypresentation. Except for this point, this case can also be applied withthe synchronous presentation methods substantially identical to those ofthe first exemplary embodiment and the supplements of the firstexemplary embodiment or the synchronous presentation announcementsubstantially identical to those of the synchronous presentation method.

In the first exemplary embodiment, the broadband content is delayed by aconstant time with respect to the broadcast content. For example, in thecase that the delay time of the broadband content to the broadcastcontent is not kept constant by an influence of transmission jitter in abroadband transmission channel, the broadcast content and the broadbandcontent are synchronously presented by properly controlling the buffer.

(9) Although the transition from the state of broadcast on and broadbandoff to the state of broadcast on and broadband on is described in thefirst exemplary embodiment, there is also a transition from the state ofbroadcast on and broadband on to the state of broadcast on and broadbandoff.

The discontinuous presentation of the broadcast content or a partiallack of the broadcast content presentation is generated in the case thatthe broadcast content presentation is switched from the delaypresentation to the normal presentation in the transition from the stateof broadcast on and broadband on to the state of broadcast on andbroadband off.

For this reason, reception device 1 may perform the synchronouspresentation announcement having such details that the discontinuouspresentation of the broadcast content or the partial lack of thebroadcast content presentation is generated to the viewer.

Controller 51 decides the details, timing, or period of the synchronouspresentation announcement, and instructs content generator 31 on thedetails, timing, or period of the synchronous presentation announcement.Content generator 31 provides the announcement having the indicateddetails at the indicated timing or period.

(10) In the first exemplary embodiment, the broadcast content and thebroadband content are synchronously presented using reception device 1in FIG. 1.

Alternatively, for example, in the case that one piece of content istransmitted through two different transmission channels, the receptiondevice can have a configuration in FIG. 9 in which the pieces of contentreceived from the two transmission channels are synchronously decoded byone decoder. In FIG. 9, a constituent unit that performs the processingsubstantially identical to that of the constituent unit in FIG. 1 isdesignated by the identical reference mark.

In reception device 1A of FIG. 9, the outputs of buffers 13 and 22 areinput to decoder 14A, and decoder 14A decodes the input data from eachof buffers 13 and 22, and outputs the decoded data to content generator31A. The output of decoder 14A is input to content generator 31A, andcontent generator 31A generates service presentation content accordingto the instruction of controller 51 using the input data.

In the case that main video is transmitted through the broadcast whileextended information is transmitted through the broadband, for example,the reception device can have a configuration in FIG. 10 in which themain video is decoded by one of decoders while the main video and theextended video are decoded by the other decoder. In FIG. 10, aconstituent unit that performs the processing substantially identical tothat of the constituent unit in FIG. 1 is designated by the identicalreference mark.

In reception device 1B of FIG. 10, the output of buffer 13 is input todecoder 14B, and decoder 14B decodes the input data, and outputs thedecoded data to content generator 31B. The output of decoder 14B isinput to content generator 31B, and content generator 31B generatespresentation content such as non-extended video according to theinstruction of controller 51 using the input data, and outputs thepresentation content to presentation section 5.

The outputs of buffers 13 and 22 are input to decoder 23B, and decoder23B decodes the input data, and outputs the decoded data to contentgenerator 32B. The outputs of decoders 14B and 23B are input to contentgenerator 32B, and content generator 32B generates presentation contentsuch as extended video according to the instruction of controller 51using the input data from each of decoders 14B and 23B, and outputs thepresentation content to presentation section 5B.

Both the cases of FIGS. 9 and 10 can be applied with the synchronouspresentation methods substantially identical to those of the firstexemplary embodiment and the supplements of the first exemplaryembodiment or the synchronous presentation announcement substantiallyidentical to those of the synchronous presentation method.

(11) Even if the time difference of the reception is generated betweenthe broadcast and the broadband, sometimes the broadcast and thebroadband are not necessarily synchronized with each other depending onthe content, and there is an option that the synchronization control isnot performed between the broadcast and the broadband. In this case,controller 51 may decide whether the synchronization control should beperformed between the broadcast and the broadband.

The necessity of the synchronization may be decided by the receptiondevice, or the broadcast organization, the business operator relating tothe broadcast organization, or other business operators may transmit adelay tolerance defined in each piece of content using the broadcast orthe broadband to the reception device. There is a method fortransmitting the delay tolerance using the AIT, a method fortransmitting the delay tolerance in the application specified by theAIT, or control information (SI) on the broadcast signal.

(12) In the first exemplary embodiment, the configuration of the bufferof reception device 1 is described with reference to FIGS. 1 and 2 byway of example. However, the buffer of reception device 1 is not limitedto the configuration in FIGS. 1 and 2 as far as the buffer has thefunction equal to that of the first exemplary embodiment.

For example, desirably the buffer is disposed at a position where amemory size can be decreased as much as possible. In the first exemplaryembodiment, the buffer is included in each of the functions such as thePES buffer, the synchronizing buffer, and the re-order buffer.Alternatively, one buffer may have a plurality of functions. The buffermay dynamically allocate a memory to each function, or a plurality offunctions may be implemented by a common memory.

The same holds true for reception devices 1A and 1B in FIGS. 9 and 10.

(13) Although the synchronization control between the broadcast and thebroadband is described in the first exemplary embodiment, thecooperating system is not limited to the cooperation of the broadcastand the broadband, but the cooperating system may be applied to thecooperation of the broadcast and the broadcast, the cooperation of thebroadband and the broadband, or signal cooperation based on at leastthree transmission channels.

(14) In the first exemplary embodiment, the multiplexing scheme isdescribed using the packet configuration defined by the MPEG2-TS system.However, there is no particular limitation to the multiplexing scheme.Examples of the multiplexing scheme include the MP4 and the RTP and MMTthat are widely used in the streaming.

(15) For example, a service in which the reception device and a contentpresenting device that is a broadband terminal such as the smartphoneand the tablet cooperate with each other is also proposed in thebroadcast and broadband cooperation service.

In this case, it is necessary to synchronously control the contentpresented by reception device 1 and the content presented by the contentpresenting device.

Examples of this kind of service include a service in which thebroadcast content is presented by the reception device while thebroadband content is presented by the content presenting device.

However, the service in which the reception device and the contentpresenting device cooperate with each other is not limited to the aboveservice. For example, there are (A) a service in which the broadbandcontent is presented by the reception device while the broadcast contentis presented by the content presenting device, (B) a service in whichparts of the broadcast content and broadband content are presented bythe reception device while a part of the broadband content is presentedby the content presenting device, (C) a service in which a part of thebroadcast content is presented by the reception device while a part ofthe broadcast content and the broadband content are presented by thecontent presenting device, (D) a service in which a part of thebroadband content is presented by the reception device while a part ofthe broadband content and the broadcast content are presented by thecontent presenting device, (E) a service in which a part of thebroadcast content and the broadband content are presented by thereception device while the broadcast content is presented by the contentpresenting device, and (F) a service in which parts of the broadcastcontent and broadband content are presented by the reception devicewhile parts of the broadcast content and broadband content are presentedby the content presenting device.

In order to provide the synchronization control between the broadcastand the broadband in the reception device and the content presentingdevice, it is necessary to notify the other party of the controlinformation such as the AIT relating to the synchronization, the delaytime between the PTSs, DTSs, or broadcast and the broadband, and thesynchronous presentation method or synchronous presentation announcementas appropriate.

In the case that the broadcast received by the reception device and thebroadband received by the tablet terminal of the cooperation terminalare synchronized with each other, it is necessary to notify thereception device of the PTS of the cooperation terminal.

In the case that the broadcast or broadband content received by thereception device is transmitted to the cooperation terminal, a burden onhardware or software of the cooperation terminal can be reduced bytransmitting the data on which the synchronization control is performedby the reception device. At this point, the reception device maycalculate the delay time generated in the broadband between thereception device and the content presenting device, and control thetiming to output the PES packets from PES buffers 71 of buffers 13 and22 in consideration of both the delay time of the broadband contentreception clock time to the broadcast content reception clock time andthe delay time generated in the broadband between the reception deviceand the content presenting device.

In both the cases, controller 51 decides the details, timing, or periodof the synchronous presentation method or synchronous presentationannouncement, and controller 51 notifies the cooperation terminal of thedecided details through broadband transmitter and receiver 41 whileissuing the instruction to the content generator.

(16) There are many use cases and synchronous presentation methods forsynchronously presenting the broadband and the broadcast according tothe content or the kind of the application.

Controller 51 has a function of being able to provide a plurality ofsynchronous presentation methods and a function of being able to controlthe presentation method relating to the synchronous presentationaccording to the synchronous presentation method, and presents theplurality of synchronous presentation methods selectable according tothe application or content to the viewer.

The viewer selects the synchronous presentation method from theplurality of selectable synchronous presentation methods by themanipulation with the input interface. The selected synchronouspresentation method is input and set to controller 51. Controller 51,manipulation input section 42, content generator 31, and presentationsection 5 perform a series of operations relating to the setting whilelinking with one another.

FIG. 11 illustrates an example of a setting menu.

In the example of FIG. 11, an animation setting and a synchronouspresentation method setting can be performed as a menu of the broadcastand broadband cooperation.

In the animation setting, for example, an animation can be set used incoupling the two discontinuous videos to each other in the synchronouspresentation screen transition.

The setting relating to the synchronous presentation method can beperformed in the synchronous presentation method setting. FIG. 12illustrates an example of the setting screen of the synchronouspresentation method. In the synchronous presentation method setting, forexample, the viewer can select the synchronous presentation methods(Type 1 and Type 2) that can be presented to the viewer in addition to amode leaving a decision to the receiving apparatus, a mode leaving thedecision to the broadcast station, a manual mode, and OFF (thesynchronous presentation is not performed).

In the case that the viewer selects the mode leaving the decision to thebroadcast station, controller 51 performs the synchronous presentationmethod described in the AIT only when the synchronous presentationmethod is set to the AIT.

In the case that the viewer selects the mode leaving the decision to thereceiving apparatus, controller 51 performs the synchronous presentationmethod, which is selected from the synchronous presentation method thatcan be presented to the viewer and the synchronous presentation methoddescribed in the AIT. The synchronous presentation method maydynamically be selected.

A selection method in the application that can be specified by the AITand a selection method with the control information (such as SI) on thebroadcast signal are also adopted instead of specifying the synchronouspresentation method by the AIT.

In the case that the viewer selects the manual mode, a manual settingscreen that is illustrated in FIG. 13 as an example is started up. Inthe example of the manual setting screen in FIG. 13, the viewer can setthe delay time between −MAX second to +MAX second in the range of −10seconds to +10 seconds. Controller 51 decides a MAX value of the delaytime according to a size of the content data and the capacity of thebuffer. The synchronous delay time calculated from the PTS is displayedas a recommended value. The viewer can change the setting of the delaytime by moving a position of a black arrow in FIG. 13. The viewer canpress a recommended value button to return the delay time to therecommended value decided by controller 51. The viewer can set the delaytime to zero by pressing a reset button (can switch the delaypresentation to the normal presentation).

When the viewer performs the manipulation to change the setting of thedelay time, the control signal indicating the delay time is output tocontroller 51. Based on the control signal, controller 51 controls thebuffer to adjust the delay.

(17) The function of controller 51 of the first exemplary embodiment maybe mounted as the software or the application. A part of the functioncan be packaged as an API (Application Programming Interface).

(Second Knowledge Underlying the Present Disclosure)

The reception device disclosed in PTL 3 receives the broadcast contentthrough the digital broadcast signal, and receives the broadband contentlinking with the broadcast content through the broadband network. Thereception device delays the broadcast content presentation based on thedifference between the PTS of the broadcast content and the PTS of thebroadband content.

In the broadband network such as the Internet, because jitter isgenerated in the transmission channel, it is necessary for the receptionside to compensate the jitter. Therefore, it is necessary for thebroadband reception device to include a de-jitter buffer thatcompensates the jitter. On the other hand, it is not necessary for thebroadcast reception device to include the de-jitter buffer. Thereception device of the broadcast and broadband cooperation receptiondevice that causes the broadcast and the broadband to cooperate witheach other includes a broadband de-jitter buffer and a broadcast delaybuffer that implements buffer delay corresponding to buffer delay of thede-jitter buffer, and it is necessary to match the playback time of thebroadband to the playback time of the broadcast.

As described above, the reception device disclosed in PTL 3 synchronizesthe broadcast content and the broadband content with each other based onthe difference between the PTS of the broadcast content and the PTS ofthe broadband content. When the large-capacity buffer is used in thesynchronization, the jitter can be compensated without performingunderflow or overflow.

However, the increase of the buffer capacity leads to a problem in thatend-to-end delay increases. In the conventional broadcast receptionsystem, there is a demand for minimizing the end-to-end delay. Even ifthe reception device sufficiently has an excess memory, it is notrealistic that the whole memory is used in the jitter compensation, butdesirably a necessary minimum memory is used in the jitter compensation.In the case that a system decoder model is defined in order to guaranteethe synchronous playback of the reception device and the buffermanagement during the decoding, it is necessary to guarantee theoperation of the reception device using a predetermined-size buffer.

In the case that the de-jitter buffer is controlled using thepredetermined-size buffer in the reception device of the broadcast andbroadband cooperation reception device, there is a high possibility ofgenerating the underflow and the overflow, and it is necessary tofurther perform, for example, the buffering of the broadband content asa measure against the underflow. For the use of the reception devicedisclosed in PTL 3, the delay time of the broadcast delay buffer isinfluenced by the control of the de-jitter buffer, the underflow or theoverflow is generated in the broadcast delay buffer, and the viewing ofthe content is influenced, whereby the operation of the broadcastreceiving apparatus is hardly guaranteed.

The inventors have studied a technical solution to the problem, andexemplary embodiments based on the solution obtained by the inventorswill be described below.

Second Exemplary Embodiment

FIG. 14 is a block diagram illustrating a configuration of receptiondevice 100 that is a broadcast and broadband cooperation receptiondevice according to a second exemplary embodiment of the presentdisclosure.

Reception device 100 includes digital broadcast receiver 111, separator112, delay buffer 113, separation buffer 114, decoder 115, broadbandtransmitter and receiver 121, separator 122, de-jitter buffer 123,separation buffer 124, decoder 125, content generator 131, controlmanager 141, and controller 151.

Digital broadcast signal received by external broadcast antenna 3 isinput to digital broadcast receiver 111. Digital broadcast receiver 111tunes a desired channel from the digital broadcast signal, performsdemodulation processing and error correction processing on the digitalbroadcast signal of the tuned desired channel to generates a transportstream, and outputs the transport stream to separator 112.

Separator 112 outputs the transport stream generated by digitalbroadcast receiver 111 to delay buffer 113 while separating thetransport stream into the video data, the audio data, the caption data,and the like. Separator 112 acquires various pieces of controlinformation included in the transport stream, outputs the PCR tocontroller 151, and outputs the control information including theinformation on the kind of the content or the control to control manager141.

Delay buffer 113 performs buffer delay corresponding to the buffer delayof de-jitter buffer 123. Delay buffer 113 adjusts the delay of thecontent data of each component, such as the video data and the audiodata, which is output from separator 112 according to input and outputtiming indicated by controller 151, and outputs the adjusted contentdata to separation buffer 114.

The video data, the audio data, and the like, which are output fromdelay buffer 113, are stored in separation buffer 114. Based on timestamp information such as the DTS acquired from a PES header of the PESpacket, separation buffer 114 outputs an elementary stream (ES) of eachcomponent such as the video data and the audio data to decoder 115 whilematching the ES output timings to each other in units of access units.Separation buffer 114 outputs the time stamp information such as the DTSacquired from the PES header to controller 151. Separation buffers 114and 124 have the function similar to that of an elementary stream bufferin the MPEG2 system.

Decoder 115 decodes the access unit of each component, such as the videodata and the audio data, which is output from separation buffer 114, andoutputs the decoded access unit to content generator 131.

Broadband transmitter and receiver 121 acquires the AV content from thecontent server provided by the business operator relating to thebroadcast organization or other business operators through the broadbandnetwork, and outputs the acquired AV content to separator 122. Examplesof the AV content provided by a broadband provider include file data,video data, and audio data.

Separator 122 separates the AV content input from broadband transmitterand receiver 121 into the video data, the audio data, and the like, andoutputs the separated data to de-jitter buffer 123. Separator 122outputs the control information including the information on the kind ofthe content and the control to control manager 141. The controlinformation is included in the AV content.

De-jitter buffer 123 absorbs the jitter of the transmission channel.De-jitter buffer 123 adjusts the delay of the content data of eachcomponent, such as the video data and the audio data, which is outputfrom separator 122 at the input and output timing indicated bycontroller 151, and outputs the adjusted content data to separationbuffer 124.

The video data, the audio data, and the like, which are output fromde-jitter buffer 123, are stored in separation buffer 124. Based on timestamp information such as the DTS acquired from a PES header of the PESpacket, separation buffer 124 outputs the elementary stream of eachcomponent such as the video data and the audio data to decoder 115 whilematching the pieces of ES output timing to each other in access units.Separation buffer 124 outputs the time stamp information such as the DTSacquired from the PES header to controller 151.

Decoder 125 decodes the access unit of each component, such as the videodata and the audio data, which is output from separation buffer 124, andoutputs the decoded access unit to content generator 131.

Content generator 131 generates presentation content using the contentdata of each component (such as the video, the audio, and the caption)output from decoder 115 and the content data of each component (such asthe video, the audio, and the caption) output from decoder 125. Thepresentation content generated by content generator 131 is output toexternal presentation section 5, and presented by presentation section5.

Control manager 141 decides the method for controlling delay buffer 113and de-jitter buffer 123 based on the information, which is relating tothe kind of the content and the control and included in the controlinformation, and the states of delay buffer 113 and de-jitter buffer123, and instructs controller 151 on the decided control method. Controlmanager 141 is described in detail later with reference to FIG. 15.

Controller 151 generates the reference clock signal using the PCR outputfrom separator 112. For example, the generated reference clock signal isused to control output timing of each buffer.

Controller 151 controls the delays of delay buffer 113 and de jitterbuffer 123 based on the time stamp information such as DTS output fromseparation buffer 114, the time stamp information such as the DTS outputfrom separation buffer 124, and the control method decided by controlmanager 141.

A configuration example of control manager 141 will be described belowwith reference to FIG. 15.

FIG. 15 is a block diagram illustrating a configuration example ofcontrol manager 141 in FIG. 14.

Control manager 141 includes control information extractor 171, buffermanager 172, monitor 173, and control method determiner 174.

Control information extractor 171 extracts the information on the kindof the content and the control from the input control information, andoutputs the extracted information on the kind of the content and thecontrol to control method determiner 174. Examples of the information onthe kind of the content and the control include information on accuracynecessary for the content synchronization and information on thepermissible end-to-end delay time of the broadcast content. For example,the control information such as the information on the kind of thecontent and the control is transmitted while multiplexed on thetransmission side. For example, in the case that the MPEG2-TS scheme isused as the multiplexing scheme, the control information is adescriptor, PSI or SI constructed with a table, and a section.

Buffer manager 172 manages a buffer size, a buffer occupied amount, anda delay time (a time interval until the output from the buffer since theinput to the buffer) with respect to delay buffer 113 and de-jitterbuffer 123, and calculates a size of the excess buffer that can be usedbased on the buffer size, the buffer occupied amount, and the delaytime.

For example, buffer manager 172 can always monitor input and outputclocks, and calculate the delay times and buffer occupied amounts ofde-jitter buffer 123 and delay buffer 113.

Buffer manager 172 can calculate the buffer occupied amounts ofde-jitter buffer 123 and delay buffer 113 by multiplying the delay timesof de-jitter buffer 123 and delay buffer 113 by an average bit rate.

When a commonly-managed buffer memory exists in addition to delay buffer113 and de-jitter buffer 123, buffer manager 172 may dynamically decidethe buffer size including the memory that can be used in the buffermemory.

Monitor 173 always monitors a possibility of generating the underflow inde-jitter buffer 123 and a possibility of generating the overflow in dejitter buffer 123, and notifies control method determiner 174 of amonitoring result.

An example of monitoring processing performed by monitor 173 of thesecond exemplary embodiment will be described below.

Monitor 173 monitors the buffer occupied amount of de-jitter buffer 123.

In the case that the buffer occupied amount of de jitter buffer 123 isless than a first threshold, monitor 173 determines the possibility ofgenerating the underflow exists, and sets an underflow flag to an onstate. On the other hand, in the case that the buffer occupied amount ofde-jitter buffer 123 is greater than or equal to the first threshold,monitor 173 determines the possibility of generating the underflow doesnot exist, and sets the underflow flag to an off state.

In the case that the buffer occupied amount of de-jitter buffer 123 isgreater than a second threshold, monitor 173 determines the possibilityof generating the overflow exists, and sets an overflow flag to the onstate. On the other hand, in the case that the buffer occupied amount ofde-jitter buffer 123 is less than or equal to the second threshold,monitor 173 determines the possibility of generating the overflow doesnot exist, and sets the overflow flag to the off state.

Monitor 173 always performs the above operation.

In the case that the possibility of generating the underflow or theoverflow exists, control method determiner 174 decides the method forcontrolling delay buffer 113 and de-jitter buffer 123 based on theexcess buffer size, the end-to-end delay, and the information on thekind of the content and the control, and notifies controller 151 of thedecided control method. The operation of control method determiner 174is described later with reference to FIG. 17.

FIG. 16 is a flowchart illustrating an example of initial operation ofdelay buffer 113 and de-jitter buffer 123 after reception device 100 inFIG. 14 starts the broadcast and broadband reception. However, in theflowchart of FIG. 16, it is assumed that neither the underflow nor theoverflow is generated in delay buffer 113 and de-jitter buffer 123. Theprocessing relating to the broadband is illustrated on the left side inFIG. 16, and the processing relating to the broadcast is illustrated onthe right side in FIG. 16.

Reception device 100 starts the broadcast reception (Step S101), andstarts the broadband reception (Step S102).

After the start of the broadband reception, de-jitter buffer 123 startsthe broadband data buffering under the control of controller 151 (StepS103). Controller 151 controls the start of the buffering of delaybuffer 113 according to the start of the buffering of de-jitter buffer123, and delay buffer 113 starts the broadcast data buffering under thecontrol of controller 151 (Step S104).

Controller 151 determines whether a buffering amount of de jitter buffer123 reaches an initial buffering amount, namely, whether de jitterbuffer 123 has completed initial buffering (Step S105). Until de-jitterbuffer 123 completes the initial buffering (No in S105), de-jitterbuffer 123 and delay buffer 113 perform the initial buffering, and theprocessing in Step S105 is performed.

When the initial buffering of de-jitter buffer 123 is completed (Yes inS105), controller 151 controls the start of data delayed outputs ofde-jitter buffer 123 and delay buffer 113. De-jitter buffer 123 startsthe delayed output of the broadband data under the control of controller151 (Step S106), and delay buffer 103 starts the delayed output of thebroadcast data under the control of controller 151 (Step S107).

Thus, delay buffer 113 is operated according to the operation of dejitter buffer 123, and the initial operation is completed.

For example, the initial buffering amount of de-jitter buffer 123 is avalue in which an expected time of the jitter to be compensated and theaverage bit rate are multiplied by each other.

The output of the normal broadcast data before the start of the delayedoutput may be started after the initial buffering of de-jitter buffer123 is completed, or started without waiting for the completion of theinitial buffering of de jitter buffer 123.

At the beginning of the output of de-jitter buffer 123, the broadbanddata in which the time is matched to the broadcast data is output basedon the time difference calculated from the time stamp information on thebroadcast data and the time stamp information on the broadband data.

In FIG. 16, delay buffer 113 has the sufficiently large size in order todelay the broadcast. However, in the case that delay buffer 113 possiblycauses the overflow before the start of the delayed output of thebroadcast data, it is necessary to perform the proper processing at thattime.

FIG. 17 is a flowchart illustrating an example of control methoddeciding operation of control method determiner 174 in FIG. 14. At thestart point of the flowchart in FIG. 17, it is assumed that receptiondevice 100 is in a steady state in which de-jitter buffer 123 and delaybuffer 113 are synchronized with each other.

Control method determiner 174 determines whether the underflow flag isset to the on state or the off state based on the monitoring result ofde jitter buffer 123 with monitor 173 (Step S151). When the underflowflag is set to the off state, namely, when the possibility of generatingthe underflow in de jitter buffer 123 does not exist (OFF in S151),control method determiner 174 determines whether the overflow flag isset to the on state or the off state based on the monitoring result ofde-jitter buffer 123 with monitor 173 (Step S152).

When the overflow flag is set to the off state, namely, when thepossibility of generating the overflow in de-jitter buffer 123 does notexist (OFF in S152), control method determiner 174 returns to theprocessing in Step S151.

When the overflow flag is set to the on state, namely, when thepossibility of generating the overflow in de-jitter buffer 123 exists(ON in S152), control method determiner 174 decides processing againstthe overflow (for example, processing of skipping the output ofde-jitter buffer 123) as the control method, and instructs controller151 on the decided processing against the overflow. In response to theinstruction, controller 151 performs the processing against the overflowon de jitter buffer 123 (Step S153).

When the underflow flag is set to the on state, namely, when thepossibility of generating the underflow in de-jitter buffer 123 exists(ON in S151), control method determiner 174 determines whether de-jitterbuffer 123 has a margin (Step S154). As to the determination in StepS154, for example, the determination that de jitter buffer 123 has themargin is made in the case that the excess buffer size of de-jitterbuffer 123, which is calculated by buffer manager 172, is greater thanor equal to a predetermined value.

When the de-jitter buffer 123 does not have the margin (No in S154),control method determiner 174 goes to the processing in Step S162.

On the other hand, when de-jitter buffer 123 has the margin (Yes inS154), control method determiner 174 determines whether delay buffer 113has a margin (Step S155). As to the determination in Step S155, forexample, the determination that delay buffer 113 has the margin is madein the case that the excess buffer size of delay buffer 113, which iscalculated by buffer manager 172, is greater than or equal to apredetermined value.

When delay buffer 113 does not have the margin (No in S155), controlmethod determiner 174 goes to the processing in Step S162.

When delay buffer 113 has the margin (Yes in S155), control methoddeterminer 174 instructs controller 151 on additional buffering of dejitter buffer 123. In response to the instruction, controller 151 stopsthe output of de jitter buffer 123, and control the additional bufferingof de-jitter buffer 123. De-jitter buffer 123 stops the output by thecontrol of controller 151, and performs the additional buffering (StepS156).

Control method determiner 174 determines whether de jitter buffer 123has completed the additional buffering (Step S157). For example, thedetermination that the additional buffering is completed is made at atime point, at which de jitter buffer 123 has the sufficient occupiedamount and there is a low possibility of generating the underflow inde-jitter buffer 123, based on the monitoring result of de-jitter buffer123 with monitor 173.

When the additional buffering of de jitter buffer 123 is not completed(No in S157), control method determiner 174 returns to the processing inStep S154.

When the additional buffering of de-jitter buffer 123 is completed (Yesin S157), control method determiner 174 determines whether the broadcastneeds to be delayed (Step S158). As to the determination in Step S158,for example, the determination that the broadcast does not need to bedelayed is made in the case that the information on the accuracynecessary for the content synchronization does not need to besynchronized.

When the broadcast does not need to be delayed (No in S158), controlmethod determiner 174 decides that the delay control of delay buffer 113is not performed as the control method, and control method determiner174 notifies controller 151 of the decided control method. In responseto the notification, controller 151 does not perform the delay controlof delay buffer 113, but delay buffer 113 outputs the broadcast datawithout delay (Step S159).

When the broadcast needs to be delayed (Yes in S158), control methoddeterminer 174 determines whether the actual end-to-end delay time fallswithin a permissible range using information on the permissibleend-to-end delay time of the broadcast content (Step S160). For example,the information on the permissible end-to-end delay time of thebroadcast content can be acquired in such a way that the transmissionside specifies the permissible end-to-end delay time of the content, andtransmits the control signal through the broadcast, and the receptiondevice receives the broadcast signal, and acquires the information onthe permissible end-to-end delay time of the broadcast content from thecontrol signal.

When the end-to-end delay time is outside the permissible range (No inS160), control method determiner 174 goes to the processing in StepS162.

When the end-to-end delay time falls within the permissible range (Yesin S160), control method determiner 174 decides that the delay controlof delay buffer 113 is performed as the control method, and notifiescontroller 151 of the decided control method. In response to thenotification, controller 151 performs the delay control of delay buffer113, and delay buffer 113 performs the delayed output operation for thebroadcast data (Step S161). In the delay control, the delay amount atdelay buffer 113 can be calculated using an input and output counter ofde jitter buffer 123 and an input and output counter of delay buffer113.

In Step S162, control method determiner 174 determines that thebroadcast and the broadband cannot be synchronized with each other.Control method determiner 174 decides that de-jitter buffer 123 anddelay buffer 113 are independently controlled as the control method soas to guarantee only the broadcast reception operation, and notifiescontroller 151 of the decided control method. In response to thenotification, controller 151 independently controls de-jitter buffer 123and delay buffer 113 (Step S162).

(Supplements of Second Exemplary Embodiment)

Supplements of the second exemplary embodiment will be described below.

(1) In the second exemplary embodiment, in the case that the delaydifference of the transmission channel exists between the broadcast andthe broadband, the reception device can have a configuration in FIG. 18.In FIG. 18, a constituent unit that performs the processingsubstantially identical to that of the constituent unit in FIG. 14 isdesignated by the identical reference mark.

Reception device 100A of FIG. 18 differs from reception device 100 inFIG. 14 in that synchronization buffer 191 is added between delay buffer113 and separation buffer 114, and that synchronization buffer 196 isadded between de-jitter buffer 123 and separation buffer 124.

Using the time stamp information such as the DTS from separation buffer114 and the time stamp information such as the DTS from separationbuffer 124, controller 151 controls the output timing of synchronizationbuffer 191 and the output timing of synchronization buffer 196 such thatthe broadcast data and the broadband data are synchronized with eachother.

(2) Even if there is the possibility of generating the underflow or theoverflow in de-jitter buffer 123, delay buffer 113 is not necessarilycontrolled.

(3) The control method deciding mechanism of the second exemplaryembodiment can be used in the case that various underflow avoidingmethods and overflow avoiding methods are used.

(4) In the case that the buffer size is previously defined in order toguarantee the buffer operation in the second exemplary embodiment, theexcess buffer size may be calculated using the defined buffer size.

In the case that de-jitter buffer 123 and delay buffer 113 cannot becontrolled by the defined buffer size, the reception operation relatingto the broadband does not need to be guaranteed.

In the case that the control cannot be performed by the defined buffersize, for example, a message indicating that the control cannot beperformed by the defined buffer size may be presented in presentationsection 5.

In the case that the control cannot be performed by the defined buffersize, information indicating that the control cannot be performed by thedefined buffer size may be fed back to the transmission side usingbroadband means.

The transmission channel information such as the actual jitter time andthe delay time of the broadcast and the broadband may be fed back to thetransmission side using the broadband means.

(5) Preferably the control in which priority is given to the operationrelating to the broadcast of the reception device is performed in thecase that the synchronization between the broadcast and the broadbandcannot be guaranteed.

In the case that the synchronization between the broadcast and thebroadband cannot be guaranteed, de-jitter buffer 123 and delay buffer113 are properly controlled while de-jitter buffer 123 is monitored,thereby guaranteeing the operation relating to the broadcast of thereception device.

(6) An option that the broadband content is changed to data having lessdelay or data having less jitter can be provided as a result of thecontrol of de jitter buffer 123. In this case, broadband transmitter andreceiver 121 notifies the content server of the option to acquire thedata having the less jitter. Thus, the stable service can be provided tothe viewer.

It is also considered that the necessity of the change of the broadcastcontent acquiring method is generated in association with the change ofthe broadband content acquisition. In this case, control manager 141changes the broadcast content acquiring method.

(7) The transmission side may multiplex and transmit the controlinformation indicating quality of the transmission channel as asignaling message, and the reception device may decide or restrict thecontrol method based on the transmitted quality. For example, in thecase that the maximum delay time expected in the broadband transmissionchannel is signaled from the transmission side as the control signalindicating the quality of the transmission channel, the reception devicemay determine whether the broadband content is to be received, orwhether the broadcast content and the broadband content are to besynchronously played back by comparing the maximum delay time to thebuffer size of the reception device.

The transmission side may multiplex and transmit the control informationindicating the recommended control method as the signaling message, andthe reception device may operates based on the transmitted recommendedcontrol method.

The transmission side may multiplex and transmit the jitter time inwhich the operation can be guaranteed by the transmission side and theinformation on the buffer sizes of de-jitter buffer 123 and delay buffer113 as the signaling message.

(8) Examples of the accuracy necessary for the content synchronizationinclude (A) unnecessity of the synchronization between one piece ofcontent and the other, (B) necessity of the synchronization accuracywithin 10 seconds, (C) necessity of the synchronization accuracy within1 second, and (D) necessity of the synchronization accuracy in frameunits.

Reception device 100 can freely decide the control method on thesynchronization and the jitter so as to satisfy the accuracy necessaryfor the content synchronization. Therefore, the control method can alsobe selected according to specification or ability of the receptiondevice. For example, when the synchronization is required at a framelevel, delay buffer 113 is controlled with high accuracy according tode-jitter buffer 123. The selection that delay buffer 113 is notcontrolled according to the control of de-jitter buffer 123 can be madewhen the synchronization is not required. Instead of notification aboutthe minimum necessary synchronization accuracy, the recommendedsynchronization accuracy may be transmitted.

The reception device may decide the control method by determining thesynchronization accuracy according to the content. For example, in thecase that the content is constructed with the video and the caption, asfar as the caption can be viewed without problems, the control may beperformed while the synchronization accuracy is degraded.

(9) The transmission side may transmit the control informationindicating whether one piece of content can solely be decoded. Forexample, when the broadcast cannot solely be decoded, it is necessary tosynchronize the broadcast and the broadband with each other. On theother hand, when the broadcast can solely be decoded, an option thatonly the broadcast content is displayed can be provided in the case thatthe synchronization cannot be performed.

(10) The transmission side may be allowed to define the permissiblejitter or de-jitter buffer amount, and transmit the jitter or de-jitterbuffer amount as the control signal.

For example, a content producer may decide the synchronization accuracyas “forced” or “not forced”, and the transmission side may transmit theinformation on the synchronization accuracy.

(11) Preferably the control information can be acquired before thedecoding is started.

In the case that MMT (MPEG Media Transport) is used as the multiplexingscheme, the information that can be acquired before the decoding isstarted may be described in CI (Composition Information), or describedin an MPT (MMT Package Table) together with an asset list. For theMPEG2-TS, the control information such as a PMT (Program Map Table) maybe used as the information that can be acquired before the decoding isstarted. In the case that MPEG-DASH (Dynamic Adaptive Streaming overHTTP) is used, the information that can be acquired before the decodingis started may be described in MPD (Media Presentation Description). Forother multiplexing systems, program information that can be acquired bythe reception device before the decoding is started may be used.

The control information is transmitted through one of or both thebroadcast and the broadband, control manager 141 acquires and analyzesthe control information before the decoding is started, and decides thecontrol methods of de-jitter buffer 123 and delay buffer 113.

(12) The buffer size may be previously defined in order to compensatethe jitter or the synchronization of the broadcast and the broadband, aconstraint condition may be further defined in order to compensate theoperation in the defined buffer size, and the buffer operation such asthe measure against the underflow or overflow may be decided based onthe constraint condition.

A total size of the de-jitter buffer, delay buffer, and synchronizationbuffer may be defined, and the operation may be compensated in the totalsize.

(13) The configurations of reception devices 100 and 100A in FIGS. 14and 18 may be modified such that the decoding is performed by onedecoder as in FIG. 9, or modified to include two content generators asin FIG. 10.

(14) The functions described in the second exemplary embodiment and thesupplements of the second exemplary embodiment may be implemented byhardware or software. A part of the functions may be implemented byhardware, and a part of the functions may be implemented by software.

(15) The content in which the jitter and the synchronization of thebroadcast and the broadband are completed may be transmitted to thecooperation device such as the tablet before the decoding of thecontent.

(16) A part of the functions described in the second exemplaryembodiment and the supplements of the second exemplary embodiment may beimplemented not only as the reception device but also as a part offunctions of a relay station.

(17) Control results of de-jitter buffer 123 and delay buffer 113 (forexample, an error message that “the broadcast and the broadband cannotbe synchronized with each other”) may be presented to the viewer, orrecorded as a report.

(18) In the second exemplary embodiment, the configuration of the bufferof reception device 100 is described with reference to FIG. 14 by way ofexample. However, the buffer of reception device 100 is not limited tothe configuration in FIG. 14 as far as the buffer has the function equalto that of the second exemplary embodiment.

For example, desirably the buffer is disposed at a position where amemory size can be decreased as much as possible. In the secondexemplary embodiment, the buffer is included in each of the functionssuch as delay buffer 113, separation buffer 114, de-jitter buffer 123,and separation buffer 124. Alternatively, one buffer may have aplurality of functions. The buffer may dynamically allocate a memory toeach function, or a plurality of functions may be implemented by acommon memory.

The same holds true for reception device 100A in FIG. 18.

(19) In the second exemplary embodiment, the MPEG2-TS system isdescribed as an example of the multiplexing scheme. However, there is noparticular limitation to the multiplexing scheme. Examples of themultiplexing scheme include the MP4 and the RTP and MMT that are widelyused in the streaming.

(Others)

The first exemplary embodiment and the supplements of the firstexemplary embodiment may properly be combined.

The second exemplary embodiment and the supplements of the secondexemplary embodiment may properly be combined.

The first exemplary embodiment, the supplements of the first exemplaryembodiment, the second exemplary embodiment, and the supplements of thesecond exemplary embodiment may properly be combined.

The first exemplary embodiment and the supplements of the firstexemplary embodiment may be applied to the second exemplary embodimentand the supplements of the second exemplary embodiment, and the secondexemplary embodiment and the supplements of the second exemplaryembodiment may be applied to the first exemplary embodiment and thesupplements of the first exemplary embodiment.

SUMMARY

The reception devices and reception methods of the exemplary embodimentsand modifications and advantageous effects thereof are summarized below.

(1) A first reception device includes: a first buffer that accumulatesand outputs a first signal received through a first transmissionchannel, the necessity of the jitter compensation being eliminated inthe first transmission channel; a second buffer that accumulates andoutputs a second signal received through a second transmission channel,the jitter compensation being required in the second transmissionchannel; a control manager that monitors whether a possibility ofgenerating underflow exists in the second buffer, and decides a methodfor controlling the first and second buffers based on excess buffersizes of the first and second buffers when the possibility of generatingunderflow exists; and a controller that controls the first and thesecond buffers based on the method for controlling the first and secondbuffers decided by the control manager.

A first reception method performed in a reception device including thefirst buffer and the second buffer, the first buffer accumulating andoutputting the first signal received through the first transmissionchannel, the necessity of the jitter compensation being eliminated inthe first transmission channel, the second buffer accumulating andoutputting the second signal received through the second transmissionchannel, the jitter compensation being required in the secondtransmission channel, the first reception method includes: monitoringwhether a possibility of generating the underflow exists in the secondbuffer; deciding the method for controlling the first and second buffersbased on the excess buffer sizes of the first and second buffers whenthe possibility of generating the underflow exists; and controlling thefirst and the second buffers based on the decided method for controllingthe first and second buffers.

Therefore, the service quality can be improved in the first signal inwhich the necessity of the jitter compensation is eliminated and thesecond signal in which the jitter compensation is required.

(2) In a second reception device, the control manager of the firstreception device further decides the control method based on the controlinformation on the accuracy necessary for the synchronization of thefirst signal and the second signal.

(3) In a third reception device, the control manager of the firstreception device further decides the control method based on theinformation on the permissible end-to-end delay time of the firstsignal.

(4) A fourth reception device includes: a first buffer that accumulatesand outputs a first signal received through a first transmissionchannel; a second buffer that accumulates and outputs a second signalreceived through a second transmission channel; a controller thatperforms synchronization control of the first and the second buffersthat relate to the synchronization of the first and second signals basedon clock time information included in the first signal and clock timeinformation included in the second signal; and an announcement sectionthat performs announcement relating to the synchronization according tothe synchronization control performed by the controller.

A second reception method performed in a reception device including thefirst buffer and the second buffer, the first buffer accumulating andoutputting the first signal received through the first transmissionchannel, the second buffer accumulating and outputting the second signalreceived through the second transmission channel, the second receptionmethod includes: performing the synchronization control of the first andthe second buffers that relate to the synchronization of the first andsecond signals based on the clock time information included in the firstsignal and clock time information included in the second signal; andperforming announcement relating to the synchronization according to thesynchronization control.

Thus, the viewer's uncomfortable feeling or discomfort can be reduced insynchronizing the first signal and the second signal with each other.

(5) In a fifth reception device, the controller performs thesynchronization control based on the input from the viewer.

Thus, the synchronization of the first signal and the second signal canbe performed as desired by the viewer.

Third Exemplary Embodiment

In the first and second exemplary embodiments, by way of example, thereception device does not select the broadband content such as thebroadband content acquisition on which the multi-cast streaming isperformed. In a third exemplary embodiment, the broadband contentselected by the reception device and the broadcast content aresynchronously presented.

In the third exemplary embodiment, in the case that the term “receptiondevice” is simply described, any one of the reception devices in FIGS.1, 9, 10, and 14 may be used as the “reception device”. The same holdstrue for the description of the component, such as the term“controller”, which is included in the reception device.

[Outline]

An outline of operation performed by the reception device and server ofthe third exemplary embodiment will be described below. The server is anexample of the transmission device. In the third exemplary embodiment,in the case that the function that can be implemented in both thebroadband server and the broadcast server is described as the “server”,the server may be either the broadband server or the broadcast server.

-   -   The server transmits information indicating whether a broadband        protocol is multi-cast and information indicating whether the        content is live while the pieces of information are included in        the control information. The reception device determines whether        the broadband content of any time can be acquired based on the        control information or whether the content to be acquired is        stored in the broadband server.    -   When the broadband content of any time can be acquired, the        reception device decides the time or acquisition timing of the        broadband content to be acquired, and acquire the broadband        content from the server.    -   When the broadband content of any time can be acquired, the        reception device pre-buffers the broadband content. The server        notifies the timing to perform pre-buffering as the control        information or the event, and the reception device starts the        pre-buffering at the timing based on the notification.    -   The reception device determines whether the broadcast content        and the broadband content can synchronously be played back from        the state of the buffer, the kind of the content, and the state        of the transmission channel. When possibly the broadcast content        and the broadband content cannot synchronously be played back,        the reception device controls the buffer, or the reception        device makes a determination on the broadband content        acquisition, and performs the control based on the        determination.    -   The server signals the accuracy necessary for the        synchronization of the broadcast content and the broadband        content or the permissible time difference of the content        presentation as the control information. The reception device        controls the presentation method and the buffer based on the        control information.    -   The server signals the accuracy necessary for the        synchronization of the broadcast content and the broadband        content or the permissible time difference of the content        presentation as the control information, and instructs the        broadband server on the broadband content to be acquired based        on the control information.

[Details]

Details of the operation performed by the reception device and server ofthe third exemplary embodiment will be described below.

For example, in a progressive download scheme such as MPEG-DASH, it isconsidered that the content having different quality is acquiredaccording to a broadband environment. It is also considered that thedata at the desired time is selected and acquired from the segmenteddata, and it is also considered that the broadband content acquiredusing a protocol such as RTSP in the streaming service is selected.

In the example of the MPEG-DASH, a plurality of pieces of video datahaving different image sizes and different coding rates are prepared inthe server with respect to one piece of video content, and the videodata is divided in units of segments. Information on the video datastored in the server is described in the MPD.

The reception device acquires the MPD from the server to analyze theMPD, decides the data to be acquired in consideration of the ability ofthe reception device and the state of the broadband transmissionchannel, and makes a request to the server. The reception deviceacquires the decided desired video data from the server using an HTTPprotocol.

In broadcast and broadband cooperation service of the third exemplaryembodiment, desirably the reception device acquires the broadbandcontent by a proper method according to broadcast service (broadcastcontent), and performs the synchronous playback. Therefore, thereception device of the third exemplary embodiment acquires the controlinformation on the broadband content acquisition, the controlinformation on the broadcast and broadband cooperation, and thebroadband content corresponding to the broadcast service.

In order to provide the broadcast and broadband cooperation service, thetransmission side can cause the control information on the broadcast andbroadband cooperation to include a broadband content transmissionscheme, information on broadband content service, information indicatingwhether clock time information on the broadband content acquisition isincluded, clock time information or timing information on the broadbandcontent acquisition, the location information on the broadband content,and the like. Each piece of information will be described below.

Examples of the broadband content transmission scheme include theMPEG-DASH scheme, the MMT scheme, and the RTP scheme. In the case thatthe broadband content transmission scheme is included in the controlinformation on the broadcast and broadband cooperation, the receptiondevice acquires the broadband content transmission scheme from thecontrol information on the broadcast and broadband cooperation, andacquires the broadband content by the reception method suitable for thebroadband content transmission scheme.

Examples of the information on the broadband content service includeinformation indicating VOD, information indicating the streaming, andinformation indicating the live.

Information indicating that the clock time information or timinginformation on the start of the broadband content acquisition isdescribed in the control information can be cited as an example of theinformation indicating whether the clock time information on thebroadband content acquisition is included. Timing information such as anevent message can be cited as an example of the timing information.

In the case that the clock time information on the broadband contentacquisition is included in the control information, the reception deviceacquires the clock time information, and controls the broadband contentacquisition, or selects the broadband content to be acquired. In thecase that the information indicating the transmission of the eventmessage is included in the control information, the reception devicemonitors the event message, and controls the broadband contentacquisition according to the event.

The clock time information on the broadband content acquisition isinformation, which is necessary for the playback the broadband contentin synchronization with the broadcast content and used to specifybroadband content acquisition timing with respect to the receptiondevice.

The reception device does not need to acquire the content based on theclock time information on the broadband content acquisition. Thereception device may transmit the control signal such that the broadcaststation determines whether the content is to be acquired based on theclock time information, or the reception device may determine whetherthe content is to be acquired based on the clock time information. Thedetermination may be made by the viewer.

Specifically, the clock time information or timing information on thebroadband content acquisition is the following pieces of information.

-   -   The clock time information or timing information on the start of        the broadband content acquisition (the information indicating        the clock time or timing at which the broadband content        acquisition should be started in order to synchronize the        broadband content with the broadcast content)    -   The clock time information or timing information on the        completion of the broadband content acquisition (the information        indicating the clock time or timing at which the broadband        content acquisition should be completed in order to synchronize        the broadband content with the broadcast content)    -   The clock time information or timing information on the        broadband content playback (the information indicating the clock        time or timing at which the broadband content should be played        back in order to synchronize the broadband content with the        broadcast content)    -   The clock time information or timing information indicating the        clock time at which the broadband content acquisition becomes        available

These pieces of clock time information may be an absolute clock timesuch as the NTP or a relative clock time to a reference clock time (suchas the PCR and the NTP) of the broadcast signal. The timing informationsuch as the event message may be transmitted as the clock timeinformation on the broadband content acquisition.

For example, the location information on the broadband content isinformation indicating a place where the broadband content is stored.

The control information may include the following pieces of informationin addition to the above pieces of information.

For example, information indicating that a program of only the broadcastis switched to a program of the broadcast and broadband cooperation orclock time information indicating the clock time at which the program ofthe broadcast and broadband cooperation is started may be included inthe control information. For example, the program of the broadcast andbroadband cooperation is a program in which the broadcast and thebroadband are synchronously played back. However, the program of thebroadcast and broadband cooperation may be a program in which thebroadcast and the broadband are not synchronously played back.

In the case that the program of only the broadcast is switched to theprogram of the broadcast and broadband cooperation, by previouslynotifying the reception side of information indicating that the programof the broadcast and broadband cooperation is started or the clock timeinformation at which the program of the broadcast and broadbandcooperation is started and previously transmitting program informationon the next program, the reception side can be instructed on thepre-buffering of the broadband content. Thus, before the clock time atwhich the broadcast program is started, the reception device canpre-acquire the program information, start the broadband contentacquisition, and perform the pre-buffering, so that the synchronousplayback of the program of the broadcast and broadband cooperation cansmoothly be performed.

In the case that the state such as a combination of the transmissionchannels constituting the program is changed, information previouslyindicating the change of the state or information indicating the clocktime at which the state is changed may be included in the controlinformation. EIT may be used to transmit these pieces of information,and these pieces of information may be described in the information onthe next program by setting a PMT current next indicator to ‘0’, andtransmitted as program information.

These pieces of information may be described in the AIT. For example, ina hybrid-cast specification, it is considered that descriptor aitidentifier info( ) indicating that the AIT (application controlinformation) is included in a descriptor of PMT information on the nextprogram. In such cases, the AIT of the next program may previously betransmitted during the broadcast of the current program. Specifically, aflag indicating whether the AIT of the next program is previouslytransmitted may be stored in the descriptor, or information that canidentify the AIT relating to the next program information may bedescribed in the AIT.

The control information may include information indicating that thebroadband server is in the state in which the broadband content can beprovided. In other words, the information is information (acquisitioninformation) indicating the state in which the broadband content can beacquired. The control information may include information clock timefrom which the broadband content can be provided. In other words, theclock time information is information (acquisition information)indicating that the broadband content can be acquired after the timingby providing notification of the timing. The control information mayindicate the acquisition information on the plurality of pieces ofbroadband content, or indicate a list of broadband content that can beprovided by the broadband server.

The control information on the broadcast and broadband cooperation maybe described in program information based on the broadcast transmissionscheme as a descriptor, or described in program information based on thebroadband transmission scheme. The control information on the broadcastand broadband cooperation may be described in program information havinganother format. The control information on the broadcast and broadbandcooperation may be described in one of these pieces of programinformation, or described in the plurality of pieces of programinformation.

The program information will be supplemented below.

For example, the program information is described in the PMT in the casethat the MPEG2-TS scheme is used. The program information may bedescribed in the MPT in the case that the MMT scheme is used, and theprogram information may be described in the MPD in the case that theMPEG-DASH scheme is used. The program information may be described inapplication control information (Application Information Table) used inthe hybrid-cast, and transmitted as a section or a data carousel.

The program information is transmitted using at least one transmissionchannel in the plurality of transmission channels such as the broadcastand the broadband. For example, sometimes the program information basedon the broadband transmission scheme is transmitted through thebroadcast.

The information indicating that the control information on the broadcastand broadband cooperation is included in the program information may bedescribed in the program information, and the information indicating thelocation information including the control information on the broadcastand broadband cooperation may be included in the program information.

A specific example of the case that the control information on thebroadcast and broadband cooperation is described in the programinformation as the descriptor will be described below.

In the case that the broadcast content is transmitted using the MPEG2-TSscheme while the broadband content is transmitted using the MPEG-DASHscheme, the descriptor corresponding to the control information may bedescribed in the PMT transmitted through the broadcast or the MPDtransmitted through the broadband. The descriptor corresponding to thecontrol information may be described in both the PMT and the MPD, theMPD may be transmitted through the broadcast, and the PMT may betransmitted through the broadband.

[Example of Content Acquiring Operation]

The broadband content acquiring operation performed by the receptiondevice of the third exemplary embodiment will be described below withreference to a flowchart. FIG. 19 is a flowchart illustrating an exampleof the broadband content acquiring operation performed by the receptiondevice of the third exemplary embodiment. In the flowchart of FIG. 19,it is assumed that the reception device is in the state in which thebroadband content can be acquired at any clock time (the state in whichthe broadband content transmission is ready).

The controller (reception device) decides a broadband content acquiringmethod based on the broadband content transmission scheme and thebroadband content service information (Step S201).

Based on the broadband content acquiring method decided in Step S201,the controller acquires the control information on the broadcast, thecontrol information on the broadband, and the control information on thebroadcast and broadband cooperation with the program informationbecoming an entry as a start point (Step S202).

The controller acquires information used to acquire the followingbroadband content (Step S203).

-   -   The controller acquires the information on the content prepared        in the server from the control information on the broadband. For        the MPD of the MPEG-DASH scheme, examples of the content        information include an image size of the video data, a coding        rate of the video data, and the clock time information on the        video data.    -   The controller acquires quality information on the broadband        transmission channel from broadband transmitter and receiver 21.    -   The controller acquires the reception device ability necessary        for the playback of the content.

In the case that the reception device plays back only the broadbandcontent, the controller can decide the broadband content based on theinformation used to acquire the broadband content. In order tosynchronously play back the broadcast content and the broadband contentin the broadcast and broadband cooperation service, the controllerfurther acquires the information on the playback of the broadcastcontent (Step S204), and decides the broadband content suitable for thesynchronous playback with the broadcast content.

Examples of the information on the playback of the broadcast contentinclude the broadcast content presentation clock time or decoding clocktime such as the PTS and the DTS, the state (such as the buffer size,the buffer use amount, the overflow, and the underflow) of the buffersuch as the delay buffer and the de-jitter buffer in the receptiondevice, and the end-to-end delay amount.

In Step S203, the reception device may acquire the clock timeinformation or timing information (the information indicating the timingrelating to the broadband content acquisition) on the broadband contentacquisition. In Step S203, the reception device may acquire theinformation indicating the state in which the broadband content can beacquired (the information indicating that the broadband content is readyin the server). In the third exemplary embodiment, these pieces ofinformation (the information relating to the broadband contentacquisition, namely the acquisition information) are received throughthe broadcast. Alternatively, the pieces of information may be receivedthrough the broadband.

Using the acquisition information, the reception device can properlyacquire the broadband content in response to the reception of thebroadcast content. The reception device acquires the broadband contentaccording to the acquisition information, whereby the possibility ofgenerating the discontinuity such as skip and stopping in the broadcastpresentation of the main content can be reduced to ensure the stablebroadcast viewing.

Based on the pieces of information acquired in Steps S203 and S204, thecontroller selects the broadband content suitable for the synchronousplayback with the broadcast content, and acquires the selected broadbandcontent from the server (Step S205).

The controller synchronously plays back the broadcast content and thebroadband content by properly controlling the buffer according to theacquired broadband content (Step S206). For example, the broadcastcontent is received in Step S206. In the third exemplary embodiment, thebuffer control method is similar to that of the first and secondexemplary embodiments, the description of the buffer control method isomitted.

The detailed processing in Step S205 will be supplemented below. In StepS205, specifically, the controller acquires the time stamp of thebroadcast content, and selects the broadband content of the clock timeat which the broadband content and the broadcast content cansynchronously be played back. The controller requests and acquires theselected broadband content from the server.

It is considered that the buffer state is monitored during thesynchronous playback of the broadcast content and the broadband content,and that decision that the synchronous playback cannot be continued ismade due to the buffer overflow or underflow. In such cases, thecontroller can continue the synchronous playback by controlling thebroadband content acquisition. As used herein, the control of thebroadband content acquisition means the control (such as pause,forwarding, and reversing) of the content acquisition.

The controller can also continue the synchronous playback by acquiringthe content at a different playback time from the server. For example,the acquisition of the content at the different playback time means thatthe broadband content at a later playback time is acquired by skippingthe broadband content acquisition, or that the broadband content at anearlier playback time is acquired by reversing the broadband contentacquisition. The control is effective in the case where the jitter ordelay of the transmission channel varies.

[Operation Example in Steady State]

The synchronous playback operation including the broadband contentacquisition in the steady state in which the de jitter buffer and thedelay buffer are synchronized with each other will be described withreference to FIG. 20. FIG. 20 is a flowchart illustrating an example ofsynchronous playback operation including the broadband contentacquisition.

In the case that the decision that the synchronous playback of thebroadcast content and the broadband content is hardly performed is madein Step S162 of FIG. 17 of the second exemplary embodiment, the controlis performed such that only the broadcast reception operation isguaranteed. On the other hand, in the flowchart of FIG. 20, theacquisition of the broadband content in which the synchronous playbackcan be performed is further tried even if the decision that thesynchronous playback of the broadcast content and the broadband contentis hardly performed is made.

In the steady state, the controller (or control manager) monitors thebuffer (such as the delay buffer, the de-jitter buffer, and thesynchronization buffer) of the reception device. Whether the synchronousplayback of the broadcast content and the broadband content is hardlyperformed is determined based on the state of the buffer (Step S251).

When the synchronous playback of the broadcast content and the broadbandcontent is hardly performed due to the overflow or the underflow evenwhen the buffer is controlled (Yes in S251), the controller selects thebroadband content to be acquired based on the broadband contentacquiring operation flow in FIG. 19 (Step S252).

The controller determines whether the broadcast content and the selectedbroadband content can synchronously be played back (Step S253). When thebroadcast content and the selected broadband content can synchronouslybe played back (Yes in S253), the controller acquires the selectedbroadband content (Step S254), and returns to the steady state toperform the pieces of processing from Step S251 again.

On the other hand, when the broadcast content and the selected broadbandcontent cannot synchronously be played back (No in S253), the controllerperforms buffer control in which only the broadcast reception operationis guaranteed (Step S255).

[First Operation Example Relating to Pre-Buffering]

In order to accurately perform the synchronous playback of the broadcastcontent and the broadband content in the broadcast and broadbandcooperation service, the broadband content may previously be acquired toperform the synchronous playback with the broadcast content. Thus, thesynchronous playback can smoothly be performed without delaying thebroadcast content.

An example in which the broadcast and broadband cooperation service isstarted in the middle of the program will be described below. FIG. 21 isa flowchart illustrating an example of operation in which the broadcastand broadband cooperation service is started in the middle of theprogram.

The controller tunes a broadcast program (broadcast station), andreceives and analyzes the program information corresponding to a serviceID of the tuned broadcast program (Step S300). For example, the programinformation is the PMT for the MPEG2-TS scheme.

The controller analyzes the program information to determine whether thetuned broadcast program relates to the broadcast and broadbandcooperation service (Step S301). Unless the program information includethe description that the program is of the broadcast and broadbandcooperation service (No in S301), the controller receives only thebroadcast content (Step S307), and plays back the broadcast content(Step S308).

When the program information include the description that the program isthe broadcast and broadband cooperation service (Yes in S301), thecontroller determines whether information on a start time (informationon the broadband content acquisition) exists in a descriptor relating toa broadband content acquisition start time (Step S302). When the starttime information exists (Yes in S302), the controller acquires the starttime. At this point, the controller also acquires the locationinformation on the broadband content. If necessary, the controllercalculates the broadband content acquisition start time based on theacquired information, and starts the broadband content acquisition atthe calculated time (Step S303).

For example, in the case that the broadband content acquisition starttime is indicated by the clock time information on the basis of PCR ofthe broadcast station, the controller starts the broadband contentacquisition when a PCR clock time played back by the reception device ismatched to a PCR clock time indicated by the start time information.

For example, in the case that the broadband content acquisition starttime is described like “T seconds before the start of the broadcastprogram”, the controller calculates the time being T seconds before thebroadcast program start time, and starts the broadband contentacquisition at that time.

A step of determining whether the broadband content can be acquired maybe provided in Step S303. Whether the broadband content can be acquiredmay be determined by querying the server by the reception device, ordetermined based on the descriptor of the program information or theevent message transmitted from the server. Whether the broadband contentcan be acquired may also be determined based on the informationtransmitted indicating the time at which the broadband content can beacquired.

When the information on the broadband content acquisition start timedoes not exist (No in S302), the controller starts the broadband contentacquisition in response to the input from the viewer such as userinterface input as a trigger (Step S306). In this case, the controllermay start the broadband content acquisition at a predetermined time, orstart the broadband content acquisition by calculating the broadbandcontent acquisition time.

The broadband content previously acquired in Steps S303 and S306 isbuffered into a memory (buffer) and the like, and output at arrival ofthe reception of the broadcast content or a synchronous playback clocktime.

Subsequent to step S303, the controller receives the broadcast content(Step S304), and synchronously plays back the broadcast content and thebroadband content (Step S305).

Even if the information on the broadband content acquisition start timeexists in Step S302, a determination step of determining whether thebroadband content is to be pre-acquired may be provided from theviewpoint of the playback ability of the reception device or the bufferability.

A descriptor including the control information in the example of FIG. 21(in this case, the information on the content acquisition start time)may be described in identical program information or different pieces ofprogram information. The transmission may be performed through at leastone transmission channel in the plurality of transmission channels ofthe broadcast and broadband. In the case that the transmission isperformed through different transmission channels, informationindicating the location of the program information is described in theprogram information becoming the entry.

The control information is described as the descriptor in the example ofFIG. 21. Alternatively, the control information may be transmitted asthe event message.

In the example of FIG. 21, the broadcast and broadband cooperationservice is started in the middle of the broadcast program. On the otherhand, in the case that the broadcast and broadband cooperation serviceis started from the beginning of the next broadcast program, it isnecessary to acquire the broadband content before the start of the nextbroadcast program. In this case, the program information on the nextbroadcast program is transmitted during provision of the previousbroadcast program.

In the case that the program information on the next broadcast programis received, the reception device determines whether the broadbandcontent of the next broadcast program can be pre-acquired, andpre-acquires the broadband content if possible. At this point, bycausing the previous program information to include the informationindicating that the provision of the next program information is startedor the location information, the reception device may recognize theexistence of the broadband content to start the program informationacquisition.

[Second Operation Example Relating to Pre-Buffering]

The broadband content buffering operation will be described by taking ahybrid-cast specification standardized by IPTV forum or ARIB as anexample. FIG. 22 is a flowchart illustrating an example of the bufferingoperation for the broadband content. In the example of FIG. 22, theinformation on the broadband content acquisition start time is notifiedas an event using the AIT control code.

The controller tunes the broadcast program (broadcast station), andreceives and analyzes the PMT of the tuned broadcast program (StepS351). The controller determines whether descriptor ait_identifier_info() indicating that the AIT is transmitted exists in the PMT (Step S352).Unless the descriptor exists in the PMT, that is, unless the AIT istransmitted (No in S352), the controller receives only the broadcastcontent (Step S353), and plays back the received broadcast content (StepS354).

When the descriptor exists in the PMT (Yes in S352), the controllerstarts the acquisition of the AIT and the monitoring (Step S355).Specifically, the controller analyzes the AIT, and acquires the locationinformation on the application included in the AIT, the broadbandcontent acquisition start clock time information, and the locationinformation.

The controller monitors the AIT application control code (Step S356),and monitors an application pre-acquiring flag (a PREFECH command in thehybrid-cast specification), namely, determines whether the applicationpre-acquiring flag exists (Step S357).

When the application pre-acquiring flag exists (Yes in S357), thecontroller pre-acquires the application (Step S360), and returns to theprocessing in Step S356. When the application pre-acquiring flag doesnot exist (No in S357), the controller monitors a broadband contentpre-acquiring flag (a PREBUFFER command in the hybrid-castspecification), namely, determines whether the broadband contentpre-acquiring flag exists (Step S358). When the information on thebroadband content acquisition start clock time does not exist in StepS355, the broadband content pre-acquiring flag does not need to bemonitored in Step S358.

When the broadband content pre-acquiring flag exists (Yes in S358), thecontroller pre-acquires the broadband content from the server to performthe buffering, and returns to the processing in Step S356. When thebroadband content pre-acquiring flag does not exist (No in S358), thecontroller monitors an application execution flag (an AUTOSTART commandin the hybrid-cast specification), namely, determines whether theapplication execution flag exists (Step S359).

The pieces of processing in Steps S356 to 358, S360, and S361 arerepeated until the application execution flag is set in Step S359 (No inS359). When the application execution flag is set (Yes in S359), thecontroller acquires the application from a place specified by thelocation information described in the AIT (Step S362). At this point,when the application is pre-acquired in Step S360, the processing inStep S362 is skipped.

The controller executes the application (Step S363), and acquires thebroadband content from the place specified by the location informationon the broadband content (Step S364). At this point, when the broadbandcontent is pre-acquired in Step S361, the processing in Step S364 isskipped.

Finally, the controller receives the broadcast content (Step S365), andsynchronously plays back the broadcast content and the broadband content(Step S366).

The operations relating to the application and broadband contentdescribed in the operation example of FIG. 22 may be performed as oneapplication, or performed while divided into a plurality ofapplications. For example, the broadband content acquisition may beperformed as a part of one application, or alternatively, an applicationperforming the broadband content acquiring operation and an applicationperforming the broadband content playback operation may be separatelyprovided and executed. In this case, the application performing thebroadband content acquiring operation is activated first, and theapplication performing the broadband content playback operation isactivated at different timing.

The location information on the broadband content may be described inthe AIT or acquired in the application.

The location information on the broadband content may be acquired byexecuting the application used to acquire only the program informationthrough the broadband transmission channel.

The information indicating the state in which the broadband content canbe acquired and the information indicating the state in which thebroadband content can be played back may be acquired by the API and thelike.

The information on the broadband content acquisition start time may bedescribed in not only the AIT control code but also the controlinformation, or the information on the broadband content acquisitionstart time may be determined based on whether another piece of controlinformation exists.

[Modifications of Third Exemplary Embodiment]

The function (operation) of the third exemplary embodiment may bemounted by either software or hardware. A part of the function ismounted as the API, and the function may be controlled from theapplication. The API that can acquire the information obtained by thefunction and the information indicating a function state may be mounted,and the information may be acquired from the application.

At this point, examples of the function state include the buffer (thedelay buffer and the de-jitter buffer) occupied amount, the end-to-enddelay time, the application state, and the broadband content acquisitionstate.

In the case that the currently-played-back program is determined to benot on air but recorded program, the reception device may acquire fromthe server the information indicating whether the application or thebroadband content is available. Unless the application or the broadbandcontent is available, the reception device may prohibit the acquisitionand execution of the application or the acquisition of the broadbandcontent.

For such cases, application control information for recorded-programplayback and broadband content pre-acquisition information forrecorded-program playback may be separately prepared in the server. Inthe case of the recorded-program playback, information for therecorded-program playback may be acquired from the server with no use ofthe on-air information.

In the third exemplary embodiment, by way of example, mainly the contentis acquired based on the broadband content acquisition start time.Alternatively, a broadband content acquisition completion clock time maybe specified, and the reception device may decide the broadband contentacquisition start time in consideration of the time necessary for thebroadband transmission or the transmission delay. In the case that theapplication control or the broadband content acquisition is performedthrough the cooperation terminal such as the tablet, the time necessaryfor the broadband content acquisition may be decided in consideration ofthe transmission delay between the cooperation terminals.

(Supplements of Third Exemplary Embodiment)

[Supplement 1: Broadband Content Acquisition]

The broadband content acquisition in FIGS. 19 and 20 will be describedin detail.

In the broadcast and broadband cooperation service, the controlinformation signaled from the transmission side, the reception devicestate, and the transmission channel state can be cited as an example ofthe information necessary for the decision of each of the delay controlmethod, the synchronization control method, and the broadband contentacquisition control method. The reception device can acquire thesepieces of information as needed. The reception device can detect thefollowing pieces of information and the state change by monitoring thepieces of information and the state.

The flow relating to the information and the state corresponds to StepsS201 to S204 in FIG. 19. Examples of the control information, thereception device state, and the transmission channel state include thefollowing items.

(1) The following pieces of information are illustrated as the controlinformation on the broadcast and broadband cooperation. (For example,the following pieces of information are stored in a meta-file such asthe PMT in the MPEG-2TS scheme and the MPT in the MMT scheme.)

-   -   Information indicating whether the program is the broadcast and        broadband cooperation program    -   Information indicating the kind of the broadcast and broadband        cooperation program    -   Information that is the content subjected to the scalable        coding, and indicates that one of basic layer data and extended        layer data is transmitted through the broadcast while the other        is transmitted through the broadband    -   Information indicating a program to which a measure against rain        attenuation (the broadcast program is switched to the broadband        content in the case that the broadcast transmission channel is        degraded due to the rain attenuation) is applied    -   Information indicating multi-view, multi-audio, and target        advertisement    -   Information indicating whether the broadcast program can solely        be decoded    -   Information indicating the synchronization accuracy necessary        for the decoding and presentation of the broadcast content and        broadband content. For example, this information indicates that        the high-accuracy synchronization is required at a frame level        or that the presentation can be performed even in the        asynchronization.    -   Information indicating whether the broadcast content and the        broadband content are a synchronization target    -   Information indicating whether the time line is synchronized    -   Information indicating whether the video is the live video or        the non-live video    -   Information indicating that the broadcast content is delayed        relative to the broadband content or that the broadband content        is delayed relative to the broadcast content. This information        may be information that indicates not the delay of individual        reception device but the delay amount expected based on line        design of the broadcast station.    -   Information indicating the end-to-end delay permissible in the        presentation of the broadcast program    -   Information indicating previously the change of the control        information

(2) The following pieces of information are illustrated as theinformation on the broadband means. For example, the information on thebroadband means is stored in the MPD of the MPEG-DASH scheme or themeta-file having the IPTVF VOD specification.

-   -   Information indicating a broadband protocol (such as http and        rtsp)    -   Information indicating uni-cast (TCP), multi-cast (UDP), or        uni-cast (UDP)

(3) The following pieces of information are illustrated as theinformation on the broadband content. For example, the information onthe broadband content is stored in the MPD of the MPEG-DASH scheme orthe meta-file having the IPTVF VOD specification.

-   -   Information indicating an attribute of the broadband content    -   Expiration date of the content    -   Viewing limit (CAS) of the content    -   Kind (resolution and transmission rate) of the content    -   Whether the broadband content of any time can be pre-acquired

(4) The following parameters are illustrated as the broadcasttransmission channel state, the broadband transmission channel state,and the delay state. The reception device acquires these parameters.

-   -   Broadband channel state    -   Jitter, QoS, and RTT    -   End-to-end delay    -   Transmission rate (band)

Delay difference between the broadcast and the broadband (the broadcastis ahead? or the broadband is ahead?)

(5) The following parameters are illustrated as the buffer state. Thereception device acquires these parameters.

-   -   Buffer capacity    -   Buffer occupied amount    -   Buffer delay amount

(6) The following parameters are illustrated as the reception devicespecification or the reception device ability. The reception deviceacquires these parameters.

-   -   Specifications    -   The number of decoders    -   Compatible browser    -   Version information and the like

(7) “Information indicating whether the control instruction is to beissued” can be cited as the information on the delay control, theinformation on the synchronization control, and the information on thecontent acquisition control method. For example, the information isstored in a meta-file such as the PMT in the MPEG-2TS scheme and the MPTin the MMT scheme.

The information indicating whether the control instruction is to beissued specifies that, for example, the broadcast station issues theinstruction on the control method, the reception device decides thecontrol method, or the user decides the control method by the usersetting.

In the case that the broadcast station issues the instruction on thecontrol method, for example, the broadcast station instructs thereception device whether the broadcast content and the broadband contentare to be synchronously presented, or instructs the reception devicewhether the broadband content is to be pre-buffered. In the case thatthe broadcast station instructs the reception device to pre-buffer thebroadband content, the broadcast station signals the time informationand the timing information.

In the case that the user decides the control method by the usersetting, the user setting includes a setting according to theinstruction of the broadcast station, a setting leaving the decision tothe reception device, and the a manual setting by the user.

[Supplement 2: Determination Whether Broadband Content can be AcquiredAnytime]

The cases that acquiring the broadband content anytime is possible andimpossible are described above. At this point, the reception device maydetermine whether the broadband content can be acquired anytime, anddecide the control details based on the determination result.

For example, whether the broadband content can be acquired anytime canbe determined by the control information signaled from the transmissionside.

1. Broadband scheme dependence

The determination can be made based on whether the broadband scheme inthe broadcast and broadband cooperation service is the uni-cast or themulti-cast. For example, the determination that acquiring the broadbandcontent anytime is impossible is made for the multi-cast.

2. Content dependence

Whether the broadband content in broadcast and broadband cooperationcontent can be acquired anytime is signaled, and the determination canbe made based on the signaled information. For example, based on thesignaled information, the determination is made as follows.

2-1. Acquiring the broadband content anytime is impossible

2-2. All pieces of the broadband content are prepared in the server, andcan be acquired anytime

2-3. It is unclear whether the broadband content can be acquired anytime(for example, the live video)

In the cases 1, 2-1, and 2-2, because the control information signaledon the transmission side is analyzed by the reception device to enablethe determination, basically the control details can be decided withoutquerying the server. Even in these cases, the control details aredecided by querying the server in the case that the determination cannotbe made by the analysis of the control information. FIG. 23 is aflowchart illustrating an example of a determination whether thebroadband content can be acquired anytime.

As illustrated in FIG. 23, the reception device analyzes the controlinformation transmitted from the server, and determines whether thebroadband content can be acquired anytime (Step S401). When thedetermination can be made by the analysis of the control information(Yes in S402), the control details are decided based on thedetermination result (Step S404). When the determination cannot be madeby the analysis of the control information (No in S402), thedetermination is made by querying the server (Step S403), and thecontrol details are decided based on the determination result (StepS404).

In the case that acquiring the broadband content anytime is impossible,for example, the buffer of the reception device is controlled using themethods of the first and second exemplary embodiments, and the delay orsynchronous presentation between the broadcast content and the broadbandcontent are controlled.

In the case that the broadband content can be acquired anytime, forexample, the buffer of the reception device and the broadband contentacquisition are controlled using the method of the third exemplaryembodiment, and the delay between the broadcast content and thebroadband content is controlled, or the broadcast content and thebroadband content are synchronously presented.

In the case 2-3, specifically, the server signals whether the broadcastcontent is the live video, and the determination that the broadcastcontent is the live video is made.

In the case that the broadcast content is the live video, there is ahigh possibility that the broadband content is not prepared in theserver. However, sometimes the broadband content is prepared in theserver. For this reason, whether the broadband content can actually beacquired is determined such that the reception device queries theserver.

The server may signal whether the broadcast is the delayed live video.This is because there is a high possibility that the broadband contentis not prepared in the server in the case that the broadcast is not thedelayed live video, and there is a possibility that the broadbandcontent is prepared in the server in the case that the broadcast isdelayed. In this case, the server may signal the information indicatinghow much the broadcast is delayed.

The actual time necessary for the reception device to acquire thebroadband content depends on the band of individual broadband line, thereception device ability, the CPU use amount, and the buffer amount.Accordingly, in the case 2-3, the transmission side (server) may signalwhether the broadband content can be acquired anytime in an environmentexpected by the transmission side, and guarantee the broadband contentacquisition on the reception side.

At this point, for example, the environment expected by the transmissionside is an environment that is fixed based on the minimum buffer sizedefined by a standard, the band of the broadband line, and the CPUability.

The determination whether the broadband content can be acquired anytimeis described above. Alternatively, whether the broadband content can beacquired anytime with respect to the broadcast content may bedetermined. For example, for the live video, the period in which thebroadband content can be acquired may be restricted in such a way thatthe determination is made whether the broadband content later than thebroadcast content by a predetermined time can be acquired.

[Supplement 3: Operation when Broadcast Content Delay Presentation isnot Permitted]

The operation for the case that the broadband content can be acquiredanytime and the case that possibly the broadband content can be acquiredany time while the delay presentation of the broadcast content is notpermitted (prohibited) will be described below.

When the delay presentation of the broadcast content that is of the maincontent is performed during the provision of the broadcast and broadbandcooperation service, the viewer has the uncomfortable feeling, but thestable broadcast service is not provided. Therefore, the control underthe condition that the delay presentation of the broadcast content isprohibited in the broadcast and broadband cooperation service will bedescribed below.

As described above, it is assumed that the determination whether thebroadband content can be acquired anytime is made based on the controlinformation or by the actually querying the server. In the followingdescription, it is assumed that the broadband content of the target forsynchronization with the broadcast content changes with time (theplurality of pieces of broadband content exist at respective clocktimes).

FIG. 24 is a flowchart illustrating an example of the operation when thedelay presentation of the broadcast content is not permitted.

The reception device acquires the delay time between the broadbandcontent and the broadcast content (Step S451). As described above, thedelay time (delay difference) between the broadband content and thebroadcast content can be acquired by the reception device. The receptiondevice determines whether the broadband content is delayed relative tothe broadcast content (Step S452).

When the broadband content is delayed relative to the broadcast content(Yes in S452), because the broadcast content cannot be delayed, thereception device acquires the broadband content at a later time (StepS453). That is, the reception device skips the frame of the broadbandcontent.

The reception device determines whether the broadband content at adesired time can be acquired (Step S457). When the broadband content atthe desired time can be acquired (Yes in S457), namely, when even thebroadband content at the later time is the broadband content at thedesired time, the reception device acquires the broadband content at thelater time, and synchronously presents the broadcast content and theacquired broadband content (Step S459).

When the broadband content at the desired time cannot be acquired (No inS457), the synchronous presentation cannot be performed. At this point,the reception device determines whether the accuracy of the decoding andpresentation of the broadcast content and broadband content ispermissible. When the accuracy of the decoding and presentation is notpermissible, only the broadcast content is presented (Step S458).

When the accuracy of the decoding and presentation is permissible, thedecoding and presentation of the broadcast content and the decoding andpresentation of the broadband content are independently controlled (StepS458). For example, in the case that the broadband content is thecaption provided to the broadcast content, because the high-accuracysynchronization is considered to be unnecessary, it is occasionallypermissible that the presentation is performed without synchronizing thebroadcast content and the broadband content.

Specifically, the case that the accuracy of the decoding andpresentation is permissible means that a time difference betweenbroadband content playback timing and broadcast content playback timingfalls within a predetermined permissible range. The case that theaccuracy of the decoding and presentation is not permissible means thatthe time difference between the broadband content playback timing andthe broadcast content playback timing is outside the predeterminedpermissible range.

On the other hand, when the broadcast content is delayed relative to thebroadband content (No in S452), the reception device determines whetherthe capacity of the delay buffer of the broadband content has a margin(whether a remaining capacity is less than a predetermined value) (StepS454).

When the buffer capacity does not have the margin (No in S454), thereception device acquires the broadband content at the time earlier thanthe currently-acquired broadband content (Step S455). When the broadbandcontent at the desired time can be acquired (Yes in S457), the receptiondevice acquires the broadband content at the desired time, andsynchronously presents the broadcast content and the acquired broadbandcontent (Step S459). In this case, usually the desired broadband contentcan be acquired. When the broadband content at the desired time cannotbe acquired, because the synchronous presentation cannot be performed,the reception device presents only the broadcast content, orindependently controls the decoding and presentation of the broadcastcontent and the decoding and presentation of the broadband content (StepS458).

When the buffer capacity has the margin (Yes in S454), the broadbandcontent is buffered and delayed (Step S456), and the broadcast contentand the broadband content are synchronously presented by matching thepresentation clock time to that of the broadcast content (Step S459).

In the case that a polarity of the delay time difference between thebroadcast content and the broadband content is inverted or possiblyinverted, the change of the state is detected, and the control 1-1 and1-2 is performed based on the detection result.

In the flowchart of FIG. 24, Steps S454 and S456 may be eliminated. Evenif the buffer capacity has the margin, the broadband content at theearlier time may be acquired. In this case, when the broadcast contentis delayed relative to the broadband content (No in S452), the receptiondevice acquires the broadband content at the time earlier than thecurrently-acquired broadband content (Step S455).

A request made by the reception device to the server for the broadbandcontent acquisition, which is performed in Steps S453 and S455, will bedescribed below.

When acquiring the broadband content from the server, the receptiondevice specifies the broadband content acquisition timing or the time(such as the PTS) of the broadband content to be acquired, and makes arequest for the broadband content acquisition.

When the broadband content at the specified time exists, the servertransmits the broadband content at the specified time to the receptiondevice. When the broadband content at the specified time does not exist,the server notifies the reception device of the non-existence of thebroadband content.

At this point, unless the broadband content at the time specified by thereception device exists, the server may transmit the broadband contentat the latest time to the reception device instead of the broadbandcontent at the specified time. The server may transmit the broadbandcontent at the time closest to the indicated broadband content (at theearlier time or the later time) to the reception device. The abovenotification and the transmission of alternative broadband content maybe combined.

Unless the broadband content at the time specified by the receptiondevice exists, the server may transmit the broadband content to thereception device based on the instruction of the reception device.

In the case that the reception device specifies the requested broadbandcontent by a function in making the request for the broadband contentacquisition, the time of the requested broadband content and anoperation instruction for the case of the non-existence of the contentare stored as an argument.

At this point, the operation instruction is not necessarily included inthe acquisition request. Alternatively, after the operation for the casethat the synchronous presentation cannot be performed is decided (StepS458), the reception device may issue the operation instruction for thecase of the non-existence of the broadband content based on the decidedoperation.

Specifically, for example, in the case that the accuracy of the decodingand presentation of the broadcast content and broadband content ispermissible, the reception device issues an instruction to make arequest for the broadband content acquisition at an alternative time,and independently performs the decoding and presentation of thebroadcast content and the decoding and presentation of the broadbandcontent. For example, in the case that the accuracy of the decoding andpresentation of the broadcast content and broadband content is notpermissible, the reception device instructs the server not to transmitthe broadband content, and presents only the broadcast content.

Unless the broadband content at the time specified by the receptiondevice exists, or unless a random access point exists at the time, thereception device may make a request for the acquisition of the broadbandcontent at the time closest to the broadband content at the specifiedtime (at the earlier time or the later time).

The presentation control of the broadcast content and the broadbandcontent, which is performed in Steps S458 and S459, will be describedbelow.

(1) Until the Preparation for the Broadband Content Presentation isCompleted

Until the preparation for the broadband content presentation iscompleted, the reception device presents only the broadcast content inthe case that the accuracy of the decoding and presentation of thebroadcast content and broadband content is required. In the case thatthe accuracy of the decoding and presentation of the broadcast contentand broadband content is not required, the reception deviceindependently decodes and presents the broadcast content and thebroadband content.

(2) After the Preparation for the Broadband Content Presentation isCompleted

The reception device starts the synchronous presentation of thebroadcast content and the broadband content in the case that only thebroadcast content is presented in (1) (in the case that the broadbandcontent presentation is stopped).

On the other hand, in the case that the broadcast content is delayedwhile the broadcast content and the broadband content are independentlydecoded and presented in (1), the broadband content is skipped toperform the synchronous presentation of the broadcast content and thebroadband content. In the case that the broadband content is presentedin (1) while the broadband content is delayed, the reception deviceretroactively (or continuously) presents the broadband content presentedin (1).

A message indicating the state (for example, a message indicatingwhether the synchronous presentation of the broadcast content and thebroadband content or the single presentation of the broadcast content isperformed) may be presented to the user in the content presentation.

In the case that the broadband content can be acquired prior to thebroadcast content, the server may signal whether the broadband contentpresentation prior to the broadcast content presentation is permitted.When the broadband content presentation prior to the broadcast contentpresentation is permitted, the reception device presents the broadbandcontent immediately after the preparation for the broadband contentpresentation is completed. When the broadband content presentation priorto the broadcast content presentation is not permitted, the receptiondevice buffers the broadband content until the preparation for thebroadcast content presentation is completed, and the reception devicesynchronously presents the broadcast content and the broadband contentafter the preparation for the broadcast content presentation iscompleted.

[Supplement 4: Delay Time Setting Method on Transmission Side]

A method for setting the delay amount of the broadcast content, which isperformed by the transmission station (transmission device), in the casethat the broadcast content is delayed will be described below. Thebroadcast content is transmitted from the transmission station to aplurality of reception devices, the reception devices having differentabilities and different broadband bands. Therefore, it is difficult toguarantee that all the reception terminals can receive the broadcastcontent while the broadcast content is delayed.

In order to change the delay amount according to the reception device,the transmission station may have a configuration in which delay modescan be switched. At this point, for example, the transmission station isprovided with a plurality of delay modes having different expectedtransmission rates of the broadband.

Specifically, the transmission station is provided with a first mode inwhich a high transmission rate is expected like an optical line and asecond mode in which a middle transmission rate is expected like CATVand ADSL.

For example, the delay amount is fixed based on the following equation.delay amount=minimum buffer size defined by standard/transmission rateexpected in each mode

The transmission station may signal the delay amount and the delay modeto the broadcast signal. In the signaling, the delay amount and thedelay mode are stored in the PMT of the MPEG-2 TS scheme or the MPT ofthe MMT scheme. Therefore, the reception device can control thereception device based on the signaled delay amount and delay mode.

In the case that the delay amount is determined to be larger than theexpected delay amount based on the signaled delay amount and the actualdelay amount, the reception device may increase the allocation of aresource of the reception device (CPU speed or the transmission rate ofthe broadband) to the broadband.

For example, in the case that the reception device is not compatiblewith the signaled delay amount, only the broadcast content ispreferentially presented.

It is considered that simultaneous transmission is performed on thesimilar pieces of content such as baseball and soccer using both thebroadcast and broadband cooperation content and the content of only thenormal broadcast. In such cases, the transmission station may transmitthe content of only the broadcast with or without delay with respect todelay transmission of the broadcast and broadband cooperation content.

In the simultaneous broadcast, the transmission station may signalinformation indicating whether each piece of content isdelay-transmitted, information indicating whether the delay differenceis generated, or information on the delay difference.

[Supplement 5: Configuration of Transmission Device]

The transmission device (specifically, the server) used in thetransmission station (broadcast station) will be supplemented. FIG. 25is a block diagram illustrating a configuration of the transmissiondevice. FIG. 26 is a flowchart illustrating an example of operation ofthe transmission device. FIG. 26 illustrates the flowchart of operationof the transmission device corresponding to the flowchart in FIG. 19.

As illustrated in FIG. 25, transmission device 300 includes encoder 301,multiplexer 302, and transmitter 303. Specifically, the components oftransmission device 300 are constructed with a microcomputer, aprocessor, or a dedicated circuit.

Transmitter 303 transmits information used to acquire the broadbandcontent to the reception device (Step S501), which corresponds to StepS203 in FIG. 19. At this point, an example of the information used toacquire the broadband content is the acquisition information. That is,transmitter 303 transmits the acquisition information through thebroadcast, the acquisition information being information used to playback broadband content transmitted through the broadband while thebroadband content is synchronized with broadcast content transmittedthrough the broadcast, the acquisition information being informationrelating to acquisition of the broadband content.

Specifically, multiplexer 302 packetizes the coded acquisitioninformation output from encoder 301, and transmitter 303 transmits theacquisition information packetized by multiplexer 302 through thebroadcast.

Transmitter 303 and transmits the broadcast content to the receptiondevice (Step S502), which corresponds to Step S206 in FIG. 19.

Specifically, multiplexer 302 packetizes the coded broadcast contentoutput from encoder 301, and transmitter 303 transmits the broadcastcontent packetized by multiplexer 302 through the broadcast.

Thus, by transmitting the acquisition information, the reception devicecan properly acquire the broadband content in response to the receptionof the broadcast content. The reception device acquires the broadbandcontent according to the acquisition information, whereby thepossibility of generating the discontinuity such as skip and stopping inthe broadcast presentation of the main content can be reduced to ensurethe stable broadcast viewing.

(Summary of Third Exemplary Embodiment)

According to one aspect of the present disclosure, a reception method inbroadcast and broadband cooperation service, the reception methodincludes: receiving broadcast content transmitted through broadcast;receiving acquisition information through the broadcast, the acquisitioninformation being information used to play back broadband contenttransmitted through broadband while the broadband content issynchronized with the received broadcast content, the acquisitioninformation being information relating to acquisition of the broadbandcontent; and acquiring the broadband content based on the receivedacquisition information.

For example, the reception method is illustrated by the flowchart inFIG. 19. In the reception method according to one aspect of the presentdisclosure, the broadband content can properly be acquired in responseto the reception of the broadcast content. By acquiring the broadbandcontent according to the acquisition information, the possibility ofgenerating the discontinuity such as skip and stopping in the broadcastpresentation of the main content can be reduced to ensure the stablebroadcast viewing.

Typically the broadcast content and the broadband content constitute onepiece of content (the content presented in one presentation section).For example, in the case that the broadcast content is video, thecaption displayed according to the video displayed by the broadcastcontent is the broadband content. In the scalable coding, for example,each frame constituting the 60-fps video is the broadcast content, andeach frame added to the broadcast content to constitute the 120-fpsvideo is the broadband content. Sometimes the broadcast content is themain video, and the broadband content is the advertisement (CM).

That is, the term “synchronization” means that the time differencebetween the broadcast content playback timing and the broadband contentplayback timing is matched to a predetermined time difference (the timedifference within a predetermined range) in order to play back one pieceof content constructed with the broadcast content and the broadbandcontent.

The acquisition information may be information indicating timingrelating to the acquisition of the broadband content.

Thus, the reception method that enables the broadband content to beproperly acquired in response to the reception of the broadcast contentcan be achieved by specifying the timing relating to the broadbandcontent acquisition from the transmission side (server).

The acquisition information may be information indicating timing atwhich the acquisition of the broadband content should be started inorder to synchronously play back the broadband content and the receivedbroadcast content.

The acquisition information may be information indicating timing atwhich the acquisition of the broadband content should be completed inorder to synchronously play back the broadband content and the receivedbroadcast content.

The acquisition information may be information indicating timing atwhich the playback of the broadband content should be started in orderto synchronously play back the broadband content and the receivedbroadcast content.

The acquisition information may be information that notifies timing toindicate that the acquisition of the broadband content is enabled at andafter the timing.

Thus, it is considered that there are various aspects of timing relatingto the broadband content acquisition.

The reception method may further include: calculating timing to startthe acquisition of the broadband content based on the receivedacquisition information; and starting the acquisition of the broadbandcontent at the calculated timing.

For example, the reception method is illustrated in Step S303 of theflowchart in FIG. 21. That is, in the case that the content acquisitionstarting time is not directly specified, the reception side maycalculate the content acquisition starting time. The pieces ofinformation, such as the reception device ability, the broadbandtransmission channel state, and the transmission delay, which aredescribed in the third exemplary embodiment may further be used in orderto calculate the acquisition start time with high accuracy.

The acquisition information may be information indicating a state inwhich the broadband content can be acquired.

The reception method may further include playing back the acquiredbroadband content while the broadband content is synchronized with thereceived broadcast content.

Only the broadcast content in the broadcast content and the broadbandcontent may be played back when the broadband content is unsuccessfullyacquired.

For example, the reception method is illustrated in Step S255 of FIG.20, Step S308 of FIG. 21, and Step S458 of FIG. 24. The broadcast andbroadband cooperation service that hardly gives the uncomfortablefeeling to the viewer can be performed by playing back only thebroadcast content in the case that the synchronization cannot beperformed.

When the acquired broadband content cannot be played back whilesynchronized with the received broadcast content, (1) the broadbandcontent and the broadcast content may be played back when a timedifference between playback timing of the broadband content and playbacktiming of the broadcast content is within a predetermined permissiblerange, and (2) only the broadcast content in the broadcast content andthe broadband content may be played back when the time difference isoutside the predetermined permissible range.

For example, the reception method is illustrated in Step S458 of FIG.24. The broadcast content and the broadband content may be played backwithin the permissible range without synchronization.

According to another aspect of the present disclosure, a transmissionmethod in broadcast and broadband cooperation service, the transmissionmethod includes transmitting acquisition information through thebroadcast, the acquisition information being information used to playback broadband content transmitted through the broadband while thebroadband content is synchronized with broadcast content transmittedthrough the broadcast, the acquisition information being informationrelating to acquisition of the broadband content.

For example, the transmission method is illustrated by the flowchart inFIG. 26. In the transmission method, the reception side can properlyacquire the broadband content in response to the reception of thebroadcast content, the possibility of generating the discontinuity suchas the skip and the stopping in the broadcast presentation of the maincontent can be reduced on the reception side, and the stable broadcastviewing can be ensured.

According to still another aspect of the present disclosure, a receptiondevice used in broadcast and broadband cooperation service, thereception device includes: a broadcast receiver that receives broadcastcontent transmitted through the broadcast, and receives acquisitioninformation through the broadcast, the acquisition information beinginformation used to play back broadband content transmitted through thebroadband while the broadband content is synchronized with the receivedbroadcast content, the acquisition information being informationrelating to acquisition of the broadband content; and a communicatorthat acquires the broadband content based on the received acquisitioninformation.

At this point, the broadcast receiver corresponds to the digitalbroadcast receiver in FIGS. 1, 9, 10, and 14, and the communicatorcorresponds to the broadband transmitter and receiver in FIGS. 1, 9, 10,and 14.

According to yet aspect of the present disclosure, a transmission deviceused in broadcast and broadband cooperation service, the transmissiondevice includes a transmitter that transmits acquisition informationthrough the broadcast, the acquisition information being informationused to play back broadband content transmitted through the broadbandwhile the broadband content is synchronized with broadcast contenttransmitted through the broadcast, the acquisition information beinginformation relating to acquisition of the broadband content.

At this point, the transmitter corresponds to the transmitter in FIG.25.

These comprehensive or specific aspects may be implemented by a system,a device, a method, an integrated circuit, a computer program, or arecording medium such as a computer-readable CD-ROM. These comprehensiveor specific aspects may be implemented by any combination of the system,the device, the method, the integrated circuit, the computer program,and the recording medium.

Other Exemplary Embodiments

Although the first to third exemplary embodiments are described above,the present disclosure is not limited to the first to third exemplaryembodiments.

In the third exemplary embodiment, the broadcast content is transmittedthrough the broadcast, and the broadband content is transmitted throughthe broadband. For example, if possible, other pieces of information(for example, control information) may be transmitted through either thebroadcast or the broadband.

In the first to third exemplary embodiments, each component may beconstructed with dedicated hardware, or constructed by executing asoftware program suitable for each component. Each component may beconstructed by a program executer such as a CPU and a processor thatreads and executes a software program recorded in a recording mediumsuch as a hard disk and a semiconductor memory.

Each component may be constructed with a circuit. These circuits may beconstructed with one circuit as a whole, or constructed with differentcircuits. Each of the circuits may be constructed with a general-purposecircuit or a dedicated circuit.

For example, in the first to third exemplary embodiments, processingperformed by a specific processor may be performed by another processor.A sequence of the plurality of pieces of processing may be changed, orthe plurality of pieces of processing may concurrently be performed.

Typically each functional block used in the above embodiments isconstructed as an LSI of an integrated circuit including input andoutput terminals. Each functional block may individually be constructedwith one chip, or a part of or all these functional blocks may beconstructed with one chip. At this point, although the term “LSI” isused, sometimes the integrated circuit is called an IC, a system LSI, asuper LSI, or an ultra LSI depending on the integration degree.

A technique of making the integrated circuit is not limited to the LSI,but the integrated circuit may be made using a dedicated circuit or ageneral-purpose processor. An FPGA (Field Programmable Gate Array) thatcan be programmed or a reconfigurable processor in which connection or asetting of a circuit cell in the LSI can be reconfigured may be usedafter the LSI is produced.

When another integrated circuit making technology with which the LSI isreplaced emerges with the progress of a semiconductor technology or byanother technology derived from the semiconductor technology, thefunctional blocks may be integrated using the integrated circuit makingtechnology. There is also a possibility of applying a biotechnology tothe integrated circuit making technology.

Although the reception device (reception method) and the transmissiondevice (transmission method) of the first to third exemplary embodimentsare described above, the present disclosure is not limited to the firstto third exemplary embodiments. Various modifications can be made bythose skilled in the art without departing from the scope of the presentdisclosure, and a combination of the components of different exemplaryembodiments may also included in the present disclosure.

The exemplary embodiments of the present disclosure include thefollowing aspects.

According to a first aspect of the present disclosure, a receptionmethod in a broadcast and broadband cooperation service, the receptionmethod includes: receiving broadcast content transmitted through thebroadcast; receiving broadband content transmitted through thebroadband; receiving acquisition information transmitted through thebroadcast, the acquisition information being information on acquisitionof the broadband content, the acquisition information being informationthat is used to play back the broadband content while the broadbandcontent is synchronized with the broadcast content; and acquiring thebroadband content based on the acquisition information.

According to a second aspect of the present disclosure, in the receptionmethod of the first aspect, the acquisition information is informationindicating timing relating to the acquisition of the broadband content.

According to a third aspect of the present disclosure, in the receptionmethod of the second aspect, the acquisition information is informationindicating timing relating to start of the acquisition of the broadbandcontent in order to synchronously play back the broadband content andthe received broadcast content.

According to a fourth aspect of the present disclosure, in the receptionmethod of the second aspect, the acquisition information is informationindicating timing relating to completion of the acquisition of thebroadband content in order to synchronously play back the broadbandcontent and the broadcast content.

According to a fifth aspect of the present disclosure, in the receptionmethod of the second aspect, the acquisition information is informationindicating timing relating to start of the playback of the broadbandcontent in order to synchronously play back the broadband content andthe broadcast content.

According to a sixth aspect of the present disclosure, in the receptionmethod of the second aspect, the acquisition information is informationproviding notification about timing relating to the acquisition of thebroadband content so as indicate that the broadband content can beacquired at and after timing.

According to a seventh aspect of the present disclosure, in thereception method of the fourth aspect, the reception method furtherincludes: calculating timing relating to start the acquisition of thebroadband content based on the acquisition information; and starting theacquisition of the broadband content at the calculated timing.

According to an eighth aspect of the present disclosure, in thereception method of the first aspect, the acquisition information isinformation indicating a state in which the broadband content can beacquired.

According to a ninth aspect of the present disclosure, in the receptionmethod of the first aspect, the reception method further includesplaying back the broadband content while the broadband content issynchronized with the broadcast content.

According to a tenth aspect of the present disclosure, in the receptionmethod of the first aspect, the broadcast content in the broadcastcontent and the broadband content is played back when the broadbandcontent is unsuccessfully acquired.

According to an eleventh aspect of the present disclosure, in thereception method of the first aspect, when the broadband content is notplayed back while synchronized with the broadcast content, (1) thebroadband content and the broadcast content are asynchronously playedback without synchronization when a time difference between playbacktiming of the broadband content and playback timing of the broadcastcontent is within a predetermined permissible range, and (2) only thebroadcast content in the broadcast content and the broadband content isplayed back when the time difference is outside the predeterminedpermissible range.

According to a twelfth aspect of the present disclosure, a transmissionmethod in a broadcast and broadband cooperation service, thetransmission method includes: transmitting broadcast content through thebroadcast; transmitting broadband content through the broadband; andtransmitting acquisition information through the broadcast, theacquisition information being information on acquisition of thebroadband content. At this point, the acquisition information isinformation that is used by a reception device to play back thebroadband content while the broadband content is synchronized with thebroadcast content.

According to a thirteenth aspect of the present disclosure, a receptiondevice used in a broadcast and broadband cooperation service, thereception device includes: a broadband receiver which, in operation,receives broadband content transmitted through the broadband; and abroadcast receiver which, in operation, receives broadcast contenttransmitted through the broadcast, and receives acquisition informationtransmitted through the broadcast, the acquisition information beinginformation on acquisition of the broadband content, the acquisitioninformation being information that is used by the reception device toplay back the broadband content while the broadband content issynchronized with the broadcast content. At this point, the broadbandreceiver acquires the broadband content based on the acquisitioninformation.

According to a fourteenth aspect of the present disclosure, atransmission device used in a broadcast and broadband cooperationservice, the transmission device includes: a broadband transmitterwhich, in operation, transmits broadband content through the broadband;and a broadcast transmitter which, in operation, transmits broadcastcontent through the broadcast, and transmits acquisition informationthrough the broadcast, the acquisition information being information onacquisition of the broadband content, the acquisition information beinginformation that is used by a reception device to play back thebroadband content while the broadband content is synchronized with thebroadcast content.

The reception method of the present disclosure can be used in thebroadcast and broadband cooperation service as a reception method forenabling the broadband content to properly be acquired in response tothe reception of the broadcast content.

What is claimed is:
 1. A reception method in a broadcast and broadbandcooperation service, the reception method comprising: receivingbroadcast content transmitted through broadcast; receiving acquisitioninformation transmitted through the broadcast, the acquisitioninformation being information on acquisition of broadband content, theacquisition information being information used to play back thebroadband content while the broadband content is synchronized with thebroadcast content; and acquiring the broadband content based on theacquisition information, wherein the acquisition information isinformation indicating timing relating to start of the acquisition ofthe broadband content in order to synchronously play back the broadbandcontent and the broadcast content, the acquisition information isinformation for matching a time difference between a playback timing ofthe broadcast content and a playback timing of the broadband content toa predetermined time difference in order to play back one piece ofcontent constructed with the broadcast content and the broadbandcontent, and when the broadband content is not played back whilesynchronized with the broadcast content, the broadband content and thebroadcast content are played back without synchronization when a timedifference between playback timing of the broadband content and playbacktiming of the broadcast content is within a predetermined permissiblerange.
 2. The reception method according to claim 1, wherein theacquisition information is information indicating timing relating tocompletion of the acquisition of the broadband content in order tosynchronously play back the broadband content and the broadcast content.3. The reception method according to claim 1, wherein the acquisitioninformation is information indicating timing relating to start of theplayback of the broadband content in order to synchronously play backthe broadband content and the broadcast content.
 4. The reception methodaccording to claim 1, wherein the acquisition information is informationproviding notification about timing relating to the acquisition of thebroadband content so as indicate that the broadband content can beacquired at and after the timing.
 5. The reception method according toclaim 1, further comprising: calculating timing relating to start of theacquisition of the broadband content based on the acquisitioninformation; and starting the acquisition of the broadband content atthe calculated timing.
 6. The reception method according to claim 1,wherein the acquisition information is information indicating a state inwhich the broadband content can be acquired.
 7. The reception methodaccording to claim 1, further comprising playing back the broadbandcontent while the broadband content is synchronized with the broadcastcontent.
 8. The reception method according to claim 1, wherein thebroadcast content in the broadcast content and the broadband content isplayed back when the broadband content is unsuccessfully acquired.
 9. Areception method in a broadcast and broadband cooperation service, thereception method comprising: receiving broadcast content transmittedthrough broadcast; receiving broadband content transmitted throughbroadband; receiving acquisition information transmitted through thebroadcast, the acquisition information being information on acquisitionof the broadband content, the acquisition information being informationused to play back the broadband content while the broadband content issynchronized with the broadcast content; and acquiring the broadbandcontent based on the acquisition information, wherein the acquisitioninformation is information indicating timing relating to start of theacquisition of the broadband content in order to synchronously play backthe broadband content and the broadcast content, the acquisitioninformation is information for matching a time difference between aplayback timing of the broadcast content and a playback timing of thebroadband content to a predetermined time difference in order to playback one piece of content constructed with the broadcast content and thebroadband content, and when the broadband content is not played backwhile synchronized with the broadcast content, the broadband content andthe broadcast content are played back without synchronization when atime difference between playback timing of the broadband content andplayback timing of the broadcast content is within a predeterminedpermissible range.
 10. A reception device used in a broadcast andbroadband cooperation service, the reception device comprising: abroadband receiver which, in operation, receives broadband contenttransmitted through broadband; and a broadcast receiver which, inoperation, receives broadcast content transmitted through broadcast, andreceives acquisition information transmitted through the broadcast, theacquisition information being information on acquisition of thebroadband content, the acquisition information being information that isused by the reception device to play back the broadband content whilethe broadband content is synchronized with the broadcast content,wherein the broadband receiver acquires the broadband content based onthe acquisition information, the acquisition information is informationfor matching a time difference between a playback timing of thebroadcast content and a playback timing of the broadband content to apredetermined time difference in order to play back one piece of contentconstructed with the broadcast content and the broadband content, theacquisition information is information indicating timing relating tostart of the acquisition of the broadband content in order tosynchronously play back the broadband content and the broadcast content,and when the broadband content is not played back while synchronizedwith the broadcast content, the broadband content and the broadcastcontent are played back without synchronization when a time differencebetween playback timing of the broadband content and playback timing ofthe broadcast content is within a predetermined permissible range.